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HARVARD UNIVERSITY 

Library of the 

Museum of 

Comparative Zoology 



BULLK/riN''"^ 



OF THE 



MUSEUM OF COMPAKATIVE ZOOLOGY 



IIAllVAUl) rXIVKHSlTV 



VOL. 131 



CAMBRIDGE, MASS., U.S.A. 
19()4 



The Cosmos Press, Inc 
Cambridge, Mass., U. S. A. 



CONTENTS 



I'AOE 

No. 1. — American Si'iders of tiik Okms Episiinis 
(Araneae: Theridiidae). By Herbert W. Levi. 
:\ran'li. lf)f)4 ' 1 

No. 2. — Fossil Mammals from the Lower Pliocene of 
Fish Lake Valley, Nevada. By John B. Clark, 
Mary R. Dawson and Albert E. Wood. Mareh, 
1964 27 

No. ■]. — American Spiders of the Genus I'iKnoucidia 
(Araneae : Thkridiidak). By IIerl)ert W. Levi. 
April li)(54 6.') 

No. 4. — The Braincase of the Paleozoic Elasmobranch 
Tamiohatis. By Alfi-ed Sherwood Komer. (1 
Plate.) April "PKU 87 

No. 5. — The Taxonomic Status of Hepiaxudon and 
Dental Ontogeny in Elasnwdontoniys and Am- 
hlyrhiza (Kodentia: Caviomorfiia). By Clayton 
E. Ray. May, 1964 107 

No. 6. — The Skeleton of the Lower Carboniferous 
Labyrinthodont FJiolidogaster pisciformis. By 
Alfred Sherwood Romer. (1 Plate.) May, 1964 . 129 

No. 7. — Early Evolution of the Dissorophid Amphib- 
ians. By Robert L. Carroll. (2 Plates.) Juiu". 
1964 Til 

No. 8. — The Genus Mioatlx na (Araneae, Araneidae) 
IN the West Indies. By Artbur M. ('bickeriii<r. 
June. 1964 " -^')1 



PAGE 

No. 9. — Revised Generic Diagnoses of the Fossil Fishes 
Megalichthys and Ecfosteorhachis (Family Os- 
teolepidae). By Keith Stewart Thomson. (1 
Plate.) July, 1964 283 

No. 10. — The Comparative Anatomy of the Snout in 
Rhipidistian Fishes. By Keith Stewart Thomson. 
August, 1964 . . . ." 313 

No. 11. — The Angles (Sauria, Iguanidae) of the Guade- 
LOUPEEN Archipelago. By James D. Lazell, Jr. 
September, 1964 . . . '. 359 

No. 12. — Anolis equestris in Oriente Province, Cuba. By 

Albert Schwartz. (1 Plate.) September, 1964 . 403 

No. 13. — The Lynx Spiders of North America, North of 
Mexico (Araneae: Oxyopidae). By Allen R. 
Brady. September, 1964 ......... 429 



Bulletin of the Museum of Comparative Zoology 
H A R YARD U N I V E R S I T Y 
Vol. 1:{1, No. I 



AMERICAN SPIDERS (»F TUK (IKXIS i:risi\rs 
( ARANEAE : THER 1 1 ) III )A H i 



Bv IIi:i;p.i:i;t AY. Lkvi 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

Mah(II 4, 19(14 



Publications Issued by or in Connection 

WITH THE 

MUSEUM OF COMPARATIVE ZOOLOGY 
AT HAHVARD COLLEGE 



Bulletin (octavo) 1863 — The current volume is Vol. 131 . 

Breviora (octavo) 1952 — No. 197 is current. 

Memoirs (quarto) 1864-1938 — -Publication was terminated with 
Vol. 55. 

JoHNSONiA (quarto) 1941 — A publication of the Department of 
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Occasional Papers of the Department op Mollusks (octavo) 
1945 — Vol. 2, no. 28 is current. 

Proceedings of tpie New^ England Zoological Club (octavo) 
1899-1948 — Published in connection with the Museum. Publication 
terminated with Vol. 24. 

The continuing publications are issued at irregular intervals in num- 
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obtained from the Publications Office of the Museum of Comparative 
Zoology, Cambridge 38, Massachusetts. 

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future volumes wall be published under Museum auspices. 

The Proceedings of the First International Symposium on Natural 
Mammalian Hibernation edited by C. P. Lyman and A. R. Dawe is 
available as volume 124 of the Museum of Comparative Zoology Bul- 
letin. Published in 1960, it consists of 26 papers and a general discus- 
sion, totalling 550 pages. Price $3.00 paper back, $4.50 cloth bound. 



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may be had upon request. 



Bulletin of the Museum of Comparative Zoology 

H A R \ A R D r N 1 \' K R S I T \ 
Vol. \-A\, No. 1 



AMEKICAX SPIDEK8 (>F THE (iKXlS i:i'L'<L\US 
(ARANEAE: THERIDIIDAE) 



By Herbert W. Levi 



CAMBEIDGE, MASS., U.S.A. 
P K I X T E D FOR THE MUSEUM 

March, 1964 



Iliill. Mils. ('(iiii|i. /(Nil., ll:iiv.ir.| riiiv., 131C1 ) :1-L'.'), Mar., ]|Mi4 

.\(i. 1 — A iiK ncd II SjH(l(rs Iff III! (Ifiiiis Episiiiiis tAraiu 

Tin ridiitliK ) 

\\\ I Ii:k'I!i:i;t \V. I.i;vi 



Many species of Episiniis jii-c known fi-oin only ;i sin;^lc spcci 
men; most species arc I'arc .Many species ai-c small and siinilai', 
and 1lie degree of sclerotizat ion of llic 1 i-ansparcni epigyna is 
liiLihly variable, makin<'' tlieir study dil'licnlt. 'flic siiialler species 
described liere were examined twice, once in lIMiO ;ind aiiain with 
belter optical equii)ment in 1I)()2. Most types of Simon were 
examined in 1958 and again in 1!>()2. In addition to tlie many 
similar, minute species, tliere aic a number of larger ones, most 
tj^uite distinct in structure and also of rare occurrence. Tiie gen- 
eric placement of these larger species is often uncertain l)ecaus(' 
of their greater divei-sity in appearance. 

The study of AmiM'ican Episiinis was made possible tlii-ough 
the help of numerons colleagues who loaned collections and per- 
mitted me to examine types. 1 would like to acknowledge witli 
thanks the loan of specimens fi'om the following collections: 
Museum National (rilistoii-e Xatnrelle. |*ai-is (.MXIlXi. by 
Prof. M. Vachon and .1. F. .le/.rMpicI ; the American .Museum of 
Natural History (AMXII) by \)v. W. -1. Certsdi: the j'.ritish 
Museum (Natural History) (UMXII) by .Air. 1). .1. Clark. .Mi-. 
K. H. Hyatt, Mr. E. Browning and Dr. (J. Owen Evans; the 
personal collection of Prof. A. .M. ( 'hickcrini:' now housed in 
the Museum of Comparative Zoology: and personal collection of 
Mrs. D. Frizzell (Dr. II. Exline) ; the Califoi-nia .\cademy of 
Sciences (CAS) by Mrs. Friz/ell and Dr. K. S. K'<,sx; the histitnl 
Hoyal des Sci(Mices Naturelh^s dc r.elgi(pic ilS.XP. i h\ \)y. .\. 
Collar! and Mr. -J. Kekenhosch ; the Scnckcnbcri:- .Museum 
(SMF) by Dr. O. Kraus; the Xatui-al History .Museum. Stock- 
holm, by Dr. L. Brnndin ; the Xaturhistoi-isches Museum. N'ienna. 
by Dr. M. P>eiei-. and specimens from .Miss I!. Zai)fe i.Mi's. C. 
Mann). I am grateful to Vv. Chr\santhus for checking' tln' lal- 
iuization of specific names. The examination of types in Kuro- 
pean museums was made ])ossible by a Xational Science Founda- 
tion (Irant (G-4317). the completion of the i-evision by a grant 
fi-om the National Institutes of Health ( Ai-()l!»44). 

KlMsixrs Latreille 

/•;/*/.v(/M/.s' I.;itrcillc, lSii!», Ceiicra (•rust.-ifciinini rt I iiscrtdriiiii, 4: :'.71. Type 
spcL-ics l)y nioiiotypy /■.■. Innicains l.iit rcillc. ISdii, of Kun.iH'. 



4 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Carapace often with a pair of horns between anterior and 
posterior median eyes. Lenses of lateral and posterior median 
eyes often on tubercles, with silvery and sometimes reddish pig- 
ment. Chelicerae small with a tooth or teeth on anterior margin, 
sometimes without teeth. First legs longest. Abdomen usually 
modified with humps, tubercles, and sometimes with small nip- 
ples, often light-colored with gray marks, streaks and sometimes 
white pigment. The smaller species have less pigment than 
larger ones. Colulus replaced by two setae. 

Palpus extremely complex, all structures proliferated, large, 
connected by large haematodocha. 




Distril)iiti(iii of Kjiisimis cognat an, iryfliropliflialvuis, tiipiciis, saJobreiusis, 
iiinii iniihis, a iiiocitKs. 



LEVI: ami:hi(a.\ i;nsiNus 5 

Spet'ics of EpisitiKs ;irc I'ouiid in ail pai'ls of tlic world, al- 
though most oeciii- ill wanner i-cyioiis. The (list ril)iit ion ol" tlic 
coninioiiost iVnierican species is illustrated by the iiiap. 

Episiiuis has luaiiy speeies in tropical Aiiiei-ica. !^^()st species 
are siiiall with little |iiL;iricnt, llie abdomen is siibl i-ian<rular, and 
tliere is a |)air of lioriis bet ween llie eyes. However, several spe- 
eies are larj^er. ]ii<i'mented, aud have the abdomen longei- lliaii 
wide. Episi]ius cognafits, the largest, has indications of horns 
between the eves ; E. rccifdisis, known only from the male and 
also large, has horns. The genitalia of males of the large sjx'cies 
are similar to those of tlie smaller ones. 

Einsinus americanus Nieolet, 1849, in Gay, Ilistoria de Chile, 
Zool., ]0: 548 is j)robably an argiopid related to Micraihrna. 

Episinus brasiliaiiiis Keyserling. 1884, Die Spinneii Amerikas, 
Theridiidae, 2(1) : L>(Hi. pi. 10. tig. 124, 9 . Female hohitype from 
IJrazil in the Xaturhistorisehes Museum. Vienna, e.xamined. is a 
feuude E. fridicatus Tjatreill(\ a EurojMnm species. Most likely 
the locality is in error. 

In the keys, "Fig." capitalized refers to this paper, "fig." in 
lower case, to the pre\ious paper ( Le\'i. llio.l, .lour. Xew York 
Ent. Soc, 62: 65-90). 

Key to mall' Episl)n(s 

l;i. Total leiifi'tli groater tliaii L'.fi inin fcaraii.Mcc more tliaii 1.0 iimi wide) 

o 

111. Tcital leiigtli less than '2.^) nun (caraiJaco 'ess than 0.9 mm wide) .5 
2a. Length of palpal tibia aliout eqnals that of cyniliiiim. 3 

21). Length of palpal tibia less than two-thirds that of cynibium 4 

3a. Conductor (at distal mosal tip) with hook (lOnf), fig. S) ; Te.xas to 

Ppi-^ cofjiiaiu.i 

3b. Conductor without sucli hook (Fig. 8) ; eastern Brazil rccifensis 

4a. Embolu,s ba.se hidden by tcgulum (1955, fig. 4); southeastern United 

States amoenus 

4b. Embolus base visible in ventral view (Pig. 15) ; Chile iypinui 

."a. Total length greater than 1.8 mm ; filiform portion of embolus of 

palpus with two bends, S-shaped (1955, fig. 13; Fig. 4) 6 

5b. Total length less than 1.7 mm; filiform portion of palpus evenly 

curved ' 

6a. Diameter of anterior median eyes more than three times that of other 

eyes; conductor as in Figure 4; Cuba, Hispaniola praiiosus 

61). Diameter of anterior median eyes less than twice that of other eves; 

conductor as in 1955, figure 13; Panama to Guianas hruneoviritiis 

7a. Conductor ti])i>ed with an ectally directed spine (Fig. 78); Trinidad 

to eastern Brazil salobrcnsis 



b BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

71). Comlurtor otherwise 8 

8a. Pnlpnl tibia equal in length or longer tlian evniliiuni 9 

81). Pali)al tibia le.ss than two-thirds cymliial lengtli 11 

9a. Embolus filament a relatively thick, short structure (Fig. o7 ) ; soutli- 
eastern Brazil , himvnijii y 

9b. Emliolus filament a relatively fine, long structure; Central America 10 

l(ta. Distal margin of embolus liase abnost transverse to long axis of cym- 
biuni : distal portion of l:)ulb witli an t'ctal iii'ojection (Fig. .50): 
Nicaragua ospus 

lOli. Distal nmrgin of cmljolus base not transverse, ectal inojection lack- 
ing (19-5.5, fig. 1-i) ; Panama ptuianicnsis: 

11a. Lengtli of palpal tibia less than one-third cyml)ial length; palpal 
bulli tipped liy two transpai'ent projections (1955, fig. 11) ; Mexico 
to Panama colima 

111). Ijcngth of paljial tibia about equal to or more than half length of 
cymbium ; Inillial tip otherwise 1- 

12a. Bulbal tip with a sclerotized elbowed piece (1955, fig. 12) ; Bahama 
Isls., Jamaica nadlcri 

12b. Bulbal tip otherwise 1.3 

13a. Distal end of palpal bulli with an ectal pointing hook (Fig. 45) ; 
Panama raticus 

13b. Distal end otherwise 14 

14a. Embolus base with a mesally directed lobe above filiform portion 
(Figs. 90-93) ; Panama to Bolivia erjithropliflialmux 

14b. Eni1)olus base without a mesally directed lobe above liase of filiform 
portion (1955, figs. 5, 7) ; Mexico 15 

15a. Ectal sclerotized margin of conductor widest on distal end (1955, 
fig. 5) juarezi 

151i. Ectal sclerotized margin of conductor widest on iiroximal end (1955, 
fig. 7) chiapensii 

Key to female Episiuus 

la. Abdomen with a large dorsal extension, liigher than long or wide (Fig. 

24) ; southeastern Brazil tercsopolis 

II). Abdomen otherwise with at most a median dorsal tubercle 2 

2a. Abdomen widest anteriorly 3 

2]j. Abdomen widest in middle or posteriorly 4 

3a. Abdomen with a median dorsal tuliercle (Fig. 23) ; Venezuela 

iniplexiis 
31). Abdomen without median dorsal tubercle (Fig. 11); Panama crnanns 
4a. Aljdomen suljspherical with a median dorsal tubercle (Figs. 30, 31); 

Peru malnrliin us 

4b. Abdouu'n otherwise 5 

5a. Abdoiiieu longer tlian wide; total length more tliau 2.4 mm fi 

51). Ahdomeii as wide as long or wider than long or if longer than wide, 

total length less than 2.2 mm 10 



LEVI: AMKHICAX Kl'lSIXUS 7 

(i;i. Alidoiiicii with ;i dorsal ilistiiict white foliimi pat tern hordercd by 
lilack (1955, fig. 34); Panama to (iiiiaiias hnnieoviridis 

lili. Abdomen otherwise 7 

7a. Ki)i{jyninii with an anterior stderotized raised kncdi (Fifj. Ki) ; alido- 

ineu jiointiMl aiiterioily (Kig. 14); Chile tj/piriis 

7li. i^piiiynuiii otherwise; alidoinen truncate anteriorly 8 

Sa. Epigyniun with a slight dei)ression liordered anteriorly and around 

sides (1955, fig. L'l ) ; total length more than 4.4 mm; Texas to 

Central Peru rofinntn.s 

Slj. Hpigynum depression not liordi'red anteriorly; total lengtli less than 

4.5 mm; eastern IT. S. west to .\laliama, Cuiia, Ilispaiiiolu . . '.' 

'.•a. I'^pigynum depression anterioi- to seminal receptacles (Figs. \, '1,; 

Culia, Hispaniola f/ratio-sufi 

'.til. Iljiigynum depression posteiior to seminal ii'ceptacles (1955, fig. 17); 

eastern U. S., ^laryland to Alabama (iniornus 

Ilia. .Xbdomen subspherical, widest in middle (Figs. IS, 20 i or diamond 

shaped (Fig. 7) ; total length 4.0 mm or more 11 

Kill. Aliilomen sulitriangulai', widest lu'ar postei'ior; total lengtli less thaii 

o.O mm 12 

11a. Abdomen with liumjis on middle of sides (Fig. 7 ) ; e])igynum with a 

scape (Fig. <i i ; seminal receptacles sausage-shaped ; Peru (ilhnstrialii.s 

lib. Abdonu'n without hunijis l' Fig. IS) or humps posterior (Fig. 20); 

epigynuni with a depression ( l''ius. 17, 22 i i ininii ndiis 

12a. Alidonu^n with a median anterioi' tubercle (F''ig. 54); Vene/.uel.a 

})imiicr<)ii(il Its 
12li. Abdomen without anterior tiibeicde \?> 

i;ia. Abdcimen with dorsal tubercles or iiijiples 14 

1Mb. AbdonuMi without dorsal tubercles or nipples 19 

14a. .\bdomen with a single median dorsal iiipi)le (Fig. 37) 15 

14b. Abdomen with several dorsal nijiples (Figs. 27, 34, 40) li! 

15a. Duet winding twice around seminal reeeptacdes (1955, fig. 31); 

-Mexico jitarczi 

I5li. Duct winding once around seminal rei cjilacdes (Fig. 38); Panama 

pavamnisis 
Ilia. Ab<lonien wiiler than long, lateral tubercles crowned by thorns (Fig. 
27); epigynum with a small central depression (Fig. 29); Jamaica . 

II nil IIS 
l(j|). Abdomen longt'r than wide or length e(|uals width (Fig. :!4 ) ; e|>i- 

gynum otherwise 17 

17a. Hpigynum with a distinct transverse lip (Fig. 36); T'anama pjinis 

17b. Epigynum otherwise 1'*^ 

ISa. Connecting ducts wound once around seminal recejitacdes (Fig. 41); 
Peru mni/oha nihil 
18b. Connecting ducts probably very short (1955, figs. 20, 27); Hispani- 
ola (lominit'iis 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

19a. Epigyniim depression with a median septum (Fig. 44) ; ducts short, 
opening into middle of ectal side of seminal receptacles (Fig. 43); 

Costa Eica, Panama vaticus 

19b. Epigynum and ducts otherwise 20 

20a. Epigynum openings in two dark spots anterior to seminal receptacles 

(Figs. 5.5, 56) ; southeastern Brazil bicorniger 

20b. Epigynum openings otherwise 21 

21a. Openings in a corner of a depression; area anterior and Ijetween sem- 
inal receptacles sclerotized (Fig. 66) ; eastern Brazil to Paraguay . . . 

nehulosus 
21b. Openings usually indistinct; area between seminal receptacles some- 
times sclerotized but not anteriorly 22 

22a. Seminal receptacles long and S-shaped (Figs. 73, 74) ; Trinidad to 

eastern Brazil salohrensis 

22b. Seminal receptacles not S-shaped 23 

23a. Duct coiling twice around receptacles (1955, fig. 31) ; Mexico . juarezi 

23b. Ducts coiling at most once around receptacles 24 

24a. Seminal receptacles spherical (1955, fig. 29); Bahama Isls., Jamaica 

7iadle)'i 
24b. Seminal receptacles ovoid or longer than wide ; Central America and 

South America 25 

25a. Epigynum with a median anterior dark spot (Fig. 49) ; connecting 
ducts not coiled completely around seminal receptacles (Fig. 48) ; 

Nicaragua aspus 

25b. Epigynum without median dark spot; connecting ducts coiled at least 

once around seminal receptacles 26 

26a. Connecting ducts entering openings from posterior (Figs. 58-61) ; 

Venezuela ^urlus 

26b. Connecting ducts entering openings from side 27 

27a. Dorsum of abdomen with a longitudinal dusky band and two cross 
bands (Fig. 72); median area of epigynum liglit (Fig. 71); Mato 

Grosso bicruciatus 

271). Dorsum of abdomen light, epigynum without such median light area 
(Figs. 81, 83, 85) ; Panama to Bolivia criitlirophihahniis 

Episinus immundus (Keyserling), new combination 
Figures 16-22, Map 

Theridium immundum Keyserling, 1884, Die Spinnen Amerikas, Theridiidae, 
2(1) : 89, pi. 4, fig. 57, 9. Two female syntypes from Le Para [Belem, 
Para], Brazil, in tlie ^luseum National d'Histoire Naturelle, Paris, ex- 
amined. Other syntypes come from Pebas, [Loreto], Peru. 

Theridium hi tuberculatum Keyserling, 1884, op. cit., 2(1 ' : !'2, pi. 4, fig. 60. 
Juvenile female liolotype from Pevas, Aniazonas, [I'ehas, Loicto, Peru], 
in the Museum National d'Histoire Naturelle, Paris, examined. NEW 
SYNONYMY. 



LEVI: AMERICAN EPISINUS 9 

Tliiimoitcs iminundis, — KcyserliiiK, 188G, op. rit., 2(2): 295. 

ThymoUes hituhcrculatus, — KcyserliiiK, 188(5, op. cit., 2(2): 295. 

Thymoiles higihbosus Eoewer, 1951, Abliandl. iiatunviss. Vcrein Biciiien, 
32: 504. New name for Thymoites hituberculatus Keyserlinfj, thouRlit 
preoccupied by Hypomma bititherculatns Wider. NEW SYNOXYMy. 

Description. Carapace rich brown with sonic silvery i-cddisli 
pigment between lateral eyes. Sternniii lijz'iit brown willi dark 
brown spots; spots on sides emjiliasize the lobes {F\\r:. ID). Leys 
banded rich dark brown on li<ilit. Doi'sum of abdomen gray 
with indistinct darker gray niaeulations; venter with some white 
pigment between epigastric groove and spinnerets. Eye region 
of carapat-e narrow, region between eyes swollen. Ej^es sub- 
equal in size, anterior median eyes tAvo-thii-ds diameter apart, 
almost touching laterals; postei-ioi' ii!C(liaii eyes one diameter 
apart, in some specimens almost touching latei'als. ("helieerae 
with two long teeth on anterior margin, none on posterior. 
Sternum with lobes on sides (Fig. 19). The abdomen is sub- 
spherical or with j)osterior humps (Figs. IS. 20 i . Total length 
of a syntype 5.2 mm. Cai'apace 2.:) mm long. 2.1 mm wiilc First 
femur, o.l mm; ])a1ella and tibia. ;!.2 mm ; nictataisus. 1.-1 mm; 
tarsus, O.S nun. Second patella and t JKia. 2.7 nun : 1 liifd. 1 .It mm : 
fourth, 2.() mm. 

Figures 16-19 Avere ])re|)an'd IVom a syntxpe s|)ccimcn from 
Belem, Brazil. 

Note. The species is (juile \ai-ialilc juiluini:' by the five speci- 
mens available. The posterior median eyes may be more or less 
close to the laterals. The hum])s of the abdomen may be almost 
missing (Fig. 18) or be distinct (Fig. 20). Both syntypes of 
E. inimuiiflKs almost lack humps; the immature holotyjie of 7'. 
hitiihi )ci(l(it mil has humps. The epigynuiii dc|)i-i'ssion may be 
surrounded by a lip (Fig. 17) oi- may lia\c a lip only on sides 
and }K)sterior (Fig. 22). One of the two syntypes fi-om Beh'm 
has the depression bordered all around, the dthei- nwr nnt. The 
intei-nal genitalia may be so liea\ily sclei'nt i/cd that the ducts 
are invisible, unless viewed fi-(»m a lateral po-sitimi. nr they may 
be translucent. 

The placement of this species in Episintts is not certain. 

Distribution. Amazon Valley. 

Records. Peru. San Martin: :Mish(|ui-yacu. 20 km XE of 
Moyobamba, Aug. 1947. 2 9 (F. AVoytkowski. A.MXin. Ifin'i- 
/(((co; Cucharas, lluallaga Valley, Feb.-April H'ol. 9 (F. Woyt- 
kowski). 



10 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Episinus typicus (Nieolet), new coinljination 
Figures 12-15, Map 

Theridion iypicum Nieolet, 1849, in Gay, Historia de Cliile, 3: ."39. Type 
from Yaldivia, Chile, lost. 

? Tlirridioit (igresic Nieolet, 1849, op. cit., p. 540. Type fvoiii ('hile, lost. 

Episinus (htsenii TuUgreii, 1902, Bill. Svensk. Yet. Ak. Han.U., 28: 14, pi. 1, 
fig. 4, 5. Female holotype from upper part of Ayseu Valley, [Aysen], 
southern Cliile in the Naturhistoriska Riksmust'et, Stocklioliii, exam- 
ined. NEW SYNONYMY. 

Xoic. This species usually has a pear-shaped abdomen (Fig. 
14-), described by Xieolot for two species. The small size in Nieo- 
let 's descriptions may indicate that he had immature specimens. 

Description. Carapace^ yellow-brown, dark brown or gray on 
each side. Sternum yellow, darker on sides. Legs yellow-brown 
with dark brown bands as wide as intermediate areas. Abdomen 
mottled, l)lack and white pigment above and with white pigment 
siDots on sides; venter gray sometimes without pigment. Cara- 
pace highest in thoracic region with a longitudinal very distinct 
thoracic depression. Eyes subequal in size in female ; posterior 
medians slightly larger than others in male. Anterior median 
eyes more than their diameter apart, almost touching laterals. 
Posterior medians their radius apart and their radius from lat- 
erals. Abdomen usually pear-slia])ed (Fig. 14), but (piite vari- 
al)le. Anterior point of abdomen overhanging carapace. Colulus 
larger than usual in the genus, almost length of setae. Total 
length of femah:" 8.5 mm. Carapace 1.4 mm long. 1.2 mm wide. 
First f(Mnur, 1.7 nun; patella and tibia, 1.8 mm; metatarsus, 1.9 
mm; tarsus. O.li mm. Second patella and til)ia, 1.2 mm; tliird. 
O.f) mm; fourth. 1.8 mm. Total length of male 2.9 mm. Cai'a]iace 
1.3 mm long, 1.1 mm wide. First femur, 2.0 mm; patella and 
tibia, 2.2 mm; metatarsus, 2.8 mm; tarsus. 1.0 mm. Second pa- 
tella and tibia, 1.2 mm; third, 1.1 mm; fourth. 2.0 mm. 

The epigynum has a central opening (Fig. V-\) . Anterior to 
the opening is a raised boss. The internal genitalia are heavily 
selerotized (Fig. 12). The ectal margin of the palpal cym])ium 
is lobed (Fig. 15). 

Records. Chile. Arauco: Peilh'm - Pille, Cord. Xahualbula. 
Jan. 1954 (L. Pena. ISNB) ; Piehinahuel. Cord. Xahualhuta. 
Dec. 1958 (L. Pefia. ISNB). ('aiiflii: Dalcahue, Fel). 1954, 9 
(L. Pena, ISNB). Osorno: 10 km E of Puy(>hue. 24 Jan. 1954 
(E. S. Ross. A. E. Michelbacher. CAS) ; La Picada en el Volcan 
()s()i-ii(.. .laii. 1958, 9 (11. /apfe); Rio (ioI-Col. Feb. 1957. S 



LEVI: AMERICAN ElMSINUS 11 

(L. Pcfia, ISXB). Lhinquihui : Carcliuapii. 'J7-12S 1<\'1». lit.')!, ?, 
i (L. IVfia, ISNB). Cliilo( : Cliaitrii. (i Fd.. 1!):)4 (L IVfia 
ISXB). 

Episinus bruneoviridis (Mcllo-Lcitao) 

FaiditHs bruncoviriclis Mcllo-Lcitao, 194.S, An. Ac-ad. Brasilcira ("icin'., I'd; 

156, figs. 4, 5, 9. Female holotypo from Cane Grove, British (uiiana in 

the British Museum, examined. 
Episinus bruneoviridis, — Levi, 1955, Jour. New Vork Knf. So... iVl: "0, 

figs. 13, 19, 20, 34, 9, <J. 

This species is readily distinguished by the striking; niarkings : 
a dorsal white folium on the long pear-shaped abdomen. 

Distribution. Panama, Trinidad to Guianas. 

Additional records. Panama Canal Zone: Barro Colorado Isl. 
(many collections); Summit; Forest Reserve; Chilibre; Fort 
Randolph (all A. M. Chiekering). 

Episinus EiMancs sp. n. 
Figures 9-11 

Type. Female holotype from Barro Colorado Island. Panama 
Canal Zone, June-July 19;j4 (A. M. Chickering:), in the Museum 
of Comparative Zoology. The specific name is an arbitrary com- 
bination of letters. 

Description. Carapace yellow-brown; area between eyes white. 
Legs yelloAv, abdomen yellowish gra}' with a transverse line of 
white pigment spots between humps and an indistinct longi- 
tudinal median dorsal band of black pigment. Anterior median 
eyes slightly smaller than others ; their diameter apart, slightly 
less than one-quarter diameter from laterals. Posterior eyes 
two-thirds diameter apart. Chelicerae without teeth. Fourth 
legs slightly longer than first. Abdomen subtriangular, widest 
anteriorly; with two tubercles (Fig. 11). Total length, 3.2 mm. 
Carapace, 1.2 mm long, 1.2 mm wide. First patella and tibia, 
2.0 mm; second, 1.4 nnn; third, 1.0 mm. Fourth femur, 2.1 mm: 
patella and tibia, 2.1 mm; metatarsus, 2.0 mm; tarsus 0.8 mm. 

The specimen is in a poor state of preservation. Thus, the 
coloration of the abdomen is not distinct. The species prol)ably 
belongs to Episinus. The area between the eyes is white as in 
some other members of the genus. 

Diagnosis. The shape of the abdomen (Fig. 11) separates the 
species from E. alhostriatus, and by the sclerotized internal geni- 
talia (Fig. 9) it is readily separated from most other Episinus 
known. 



12 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Episinus albostriatus (Simon), new combination 
Figures 5-7 

Episinopsis albostriafus Simon, 1895, Ann. Soe. ent. France, 64: 136. Fe- 
male liolotype from Pebas, [Loreto], Peru, in the Museum National 
d'Histoire Naturelle, Paris, examiiied. 
Description. Carapace brown, region between eyes lightest. 
Sternum, legs brown. Abdomen with dark gray blotches on 
dorsum ; venter mostly gray. Short horns between eyes. Eyes 
about subequal in size ; laterals on slight tubercles. Anterior 
median eyes less than one diameter apart, almost touching lat- 
erals. Posterior median eyes less than one diameter apart; less 
than one diameter from laterals. Abdomen about as wide as long ; 
a hump on each side (Fig. 7). Epigynum Avith a short scape 
(Fig. 6). Total length 4.2 mm. Carapace 1.6 mm wide, 1.4 mm 
long. First femur, 2.4 mm ; patella and tibia, 2.5 mm ; metatar- 
sus, 2.6 mm. Second patella and tibia, 1.7 mm; third, 1.3 mm; 
fourth, 2.3 mm. 

Episinus recifensis sp. n. 
Figure 8 

Type. Male holotype from Recife, Pernambuco, Brazil, in the 
Senckenberg Museum (no. RII /6323/1). The species is named 
after the type locality. 

Description. Carapace yellow, white between eyes, some gray 
on sides and a narrow gray line around margin. Sternum, legs 
yellow. Abdomen whitish with a pair of long gray streaks an- 
teriorly on dorsum and four pairs of gray spots posteriorly; 
whitish above spinnerets, which are surrounded by gray. Venter 
of abdomen mostly white. Carapace with two swollen horns be- 
tween eyes, which are white. Anterior median eyes larger than 
posterior medians, much larger than anterior lateral eyes, almost 
twice their diameter. Anterior median eyes one-third their 
diameter apart, touching laterals. Posterior eyes their radius 
apart. Abdomen 1.6 times longer than wide, oval in shape. 
There are no indications of humps on the abdomen of the male. 
Total length 3.3 mm. Carapace 1.0 mm long, 1.0 mm wide. First 
femur, 2.5 mm ; patella and tibia, 2.9 mm ; metatarsus, 2.8 mm : 
tarsus, 1.0 mm. Second patella and tibia, 1.6 mm; third, 1.1 
mm; fourth, 2.3 mm. 

Diagnosis. The palpal tip (Fig. 8) and longer eye horns se]i- 
arate this species from E. cognatus. 



LEVI: AMERICAN El'ISINTS 13 

Ei'Ksixus coGNATUs 0. P.-Caml)ri(Ifjfe 
Map 

/ Episinus longipcs Kcysei'linjj:, 1884, Die S|iiiiiicii Aiucrikas, Thoriiliidao, 
2 (1): 207, pi. 10, fig. 125, 9,6. Male and female syntypes from 
Monterico, [900 m elev., Ayaciicho, prov. Huaiita], Peru, in the Polish 
Academy of Sciem-es, Warsaw, ai)i)areiit]y lost. DOUBTFUL SYN- 
ONYMY. 

Episiniis cogiuifns O. P. - Cambridge, 1893, Biologia Centrali-Aniericaiia, 
Araneidea, 1 : 109, p. 15, tig. 2, $ . Male holotype from Teapa, 
[Tabasco], Mexico, in the British Museum. — Levi, 1955, Jour. New 
York Eiit. Soc, 62: 71, figs. 8-10, 21, 22, 33, 41, $, S. 

h'jiisiniipsis simplifronti Simon, 1897, Proc. Zool. Soc. London, p. 800. .lu- 
venile holotype from St. Vincent Isl., Lesser Antilles, in the British 
Museum, examined. NEW SYNONYMY. 

Note. Keyserling 's 1884 description fits this species. His speci- 
men was sliji'htly larger than the ones I have examined. The illus- 
trations match this species, although the epigynum of the Keyser- 
ling specimen seems to have been covered by secretion, as is 
common in this species. Unfortunately the type is lost, and 
thus the synonymy remains uncertain. 

The central sclerotized area of the ej)igyiial depression is 
larger and the depressed area has a slightly different shape in 
Peruvian specimens. 

Distribution. Texas to Central Peru, Amazon (Map). 

Additional records. Costa Rica. San Jose (E. Schmidt, 
AMNH). Panama: El Valle (A. M. Chickering). Panama Canal 
Zone. Barro Colorado Isl. (many collections) ; Summit (A. M. 
Chickering) ; Experimental Gardens (A. M. Chickering). Ecua- 
dor. Guayus: Colonche, 1941 (R. W. Landes) ; ]\Iilagro, Jan. 
1943, juv. 6 (H. E., D. L. Frizzell). Peru. Huanuco: Tingo 
Maria, Oct. 1946, 9 , Dec. 1946, $ (J. C. Pallister, AMNH) ; 
Oct. 1954 (E. I. Schlinger, E. S. Ross, CAS). Brazil. Amazonas: 
Manaus, Sept. 1962, 9 (W. L. Brown). 

Episinus gratiosus Bryant 
Figures 1-4 

Episinus cjratiosus Bryant, 1940, Bull. Mus. Comp. Zool., 86: 313, fig. 65, 
9 . Female holotype from Pico Turquino, 500 m, Oriente, Cuba, in the 
Museum of Comparative Zoology, examined. 

Meotipa Clementina, — Bryant, 1940, ibid., 86: 314, figs. 79, 80, S. Not 
M. clementinae Petrunkevitch. 
Description. Carapace, sternum yellow-brown with some 

darker marks. Legs vellow-brown with darker brown bands. 



14 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Abdomen with white pigment spots on dorsum, densest between 
tubercles. Sides of abdomen slightly darker, venter gray. Di- 
ameter of anterior median eyes larger than that of other eyes. 
Anterior median eyes of female one and one-half diameters 
apart, almost touching laterals; posterior median eyes one and 
one-half diameters apart, one diameter from laterals. Anterior 
median eyes of male one diameter apart almost touching later- 
als ; posterior median eyes two diameters apart, one and one- 
half diameters from laterals. The abdomen is longer than wide 
(Fig. 3). There are two tubercles, one on each side, close to 
the posterior end. Total length of female 3.2 mm. Carapace 1.0 
mm long, 0.9 mm wide. First femur, 1.8 mm; patella and tibia, 
1.9 mm; metatarsus, 1.9 mm; tarsus, 0.5 mm. Second patella and 
tibia, 1.1 mm; third, 0.8 mm; fourth, 1.7 mm. Total length of 
male 2.2 mm. Carapace 0.94 mm long, 0.89 mm wide. First 
femur, 2.22 mm ; patella and tibia, 2.24 mm ; metatarsus, 2.31 
mm; tarsus, 0.73 mm. Second patella and tibia, 1.07 mm; third, 
0.81 mm ; fourth, 1.82 mm. 

Records. Cuha. Las Villas: Soledad, April 1936, S (P. J. 
Darlington). Oriente : S. side Pico Turquino, 1100 m, June 
1936, 9 (P. J. Darlington). Haiti. Hills near Port-au-Prince, 
600 m, 2 Oct. 1934, 9 (P. J. Darlington). 

Episinus amoenus Banks 

Map 

Episinus amoenus Banks, 1911, Proc. Acad. Nat. Sci. Philadelphia, fi.T : 445, 
figs. 13, 15. Male and female syntypes from the Swananoa Eiver, North 
Carolina, in the Museum of Comparative Zoology, examined. — Levi, 
1955, Jour. New York Ent. Soc, 62 : 68, figs. 4, 17, 18, 32, 39, 9 , $. 

Distribution. Eastern United States from Maryland to Florida 
and Alabama. 

Episinus malachinus (Simon), new combination 
Figures 30-33 

Janulus malachinus Simon, 1895, Ann. Soc. ent. France, 64: 135. Two fe- 
male syntypes from Pebas, [Loreto], Peru, in the Museum National 
d 'Histoire Naturelle, Paris, examined. 
Description. The specimens, almost colorless, are yellowish 
white in alcohol except for sligiit pigment behind anterior me- 
dian eyes, some silvery spots around other eyes, and some white 
pigment spots on dorsum and posterior of abdomen. Eye re- 
gion with two large horns. Eyes on tubercles, lens of anterior 
median eyes larger than that of othei's. Abdomen snbspherical 



LEVI : AMERICAN EI'ISINUS 15 

with a median dorsal tubercle (Figs. 30, 31). Total length 2.1 
iiiiii. Carapace 0.68 nun long, 0.61 mm wide. First femni-, 1.58 
mill; patella and tibia, 1.52 mm; metatarsus, 1.4H mm; tarsus, 
O.M) mm. Second patella and tibia, 0.80 mm; third, 0.56 mm; 
fourth. l.OS mm. 

Episinus teresopolis sp. n. 
Figures 24-26 

Type. Female holotype, from Teres6|)()Iis, Est. liio de Janeiro, 
Brazil, March 1946 (II. Sick), in the American Museum of Nat- 
ural History. The specific nanu^ is a noun in apposition after 
the type locality. 

Description. Carapace yellowish-white with a reddish sj)ot on 
clypeus. Sternum, legs yellow-white. Abdomen with white pig- 
ment spots on dorsum and a red spot on each side. Eyes sub- 
equal in size. Anterior median eyes one diameter apart. Pos- 
terior median eyes one diameter apart, almost touching laterals. 
Horns between eyes. Abdomen with a dorsal i)rojection (Fig. 
24). Total length 1.5 m. Carapace 0.60 mm long, 0.52 mm M'ide. 
First femur, 0.98 mm; patella and tibia, 1.01 mm; metatarsus, 
0.70 mm ; tarsus, 0.43 mm. Second patella and tibia, 0.73 mm ; 
third, 0.50 mm ; fourth, 0.78 mm. 

Diagnosis. Episinus teresopolis may be tlie same as E. ini- 
plexus known only from an immature specimen from Venezuela. 
Both have a dorsal extension on the abdomen by which they 
differ from all other Episinus species. 

Records. One 9 paratype collected with ty])e. 

Episinus implexus (Simon) 

Figure 23 

Ilyocrca implexa Simon, 1894, Histoire Naturelle ties A laigiieos, 1: 559; 
1895, Ann. Soc. ent. France, 64: 146. Juvenile holotyi)e from San 
Estel)an, [Aragua], Venezuela, in the Museum National d 'Histoire 
Naturelle, Paris, examined. 

The type examined is a juvenile and cannot be placed, al- 
though the abdomen shap(> (P^'ig. 23) may be diagnostic. 

Episinus dominicus Levi 

Episinus dominicus Levi, 1955, Jour. New York Ent. Soi-., 62: 77, figs. L'6. 

•21, 3s, 9. Female holotype from Valle de Polo, Dominicnn tJeiiulilic, 

in the American Museum of Natural History. 
Distrihution. Known from only the type specimen from His- 
paniola. 



16 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Episinus unitus sp. n. 
Figures 27-29 

Type. Female holotype, from 3 km south of Unity Valley, 
St. Ann Parish, Jamaica, 9 Dec. 1954 (A. M. Nacller), in the 
American Museum of Natural History. The specific name is an 
arbitrar}' combination of letters. 

Description. Carapace gray with a lighter V-shaped mark; 
eyes reddish. Sternum graj' . Legs yellow-white. Abdomen gray 
with some white spots on sides; venter lighter with a reddish 
cast. Anterior median eyes larger than others, less than one 
diameter apart, almost touching laterals. Posterior median eyes 
one diameter aj^art, touching laterals. Horns between eyes. 
Abdomen with seven dorsal nipples in a transverse row (Fig. 
27). Total length 1.4 mm. Carapace 0.65 mm long, 0.60 mm 
wide. First femur, 1.17 mm; patella and tibia, 1.27 mm; meta- 
tarsus, 1.17 mm. Second patella and tibia, 0.80 mm; third, 0.52 
mm ; fourth, 0.91 mm. 

Diagnosis. Like E. moyohamha, E. pyrus and E. dominicus, 
the abdomen has numerous nipples (Fig. 27). The small distinct 
median depression of the epigynum (Fig. 29) and the shape of 
the seminal receptacles (Fig. 28) separate the species. 

Record. One ? and juvenile paratypes collected with type. 

Episinus moyobamba sp. n. 
Figures 40-42 

Type. Female holotype from Moyobamba, San Martin, Peru, 
20 Dec. 1946 ^J. C. Pallister), in the American Museum of Nat- 
ural History. The specific name is a noun in apposition after 
the type locality. 

Description. Carapace, sternum, legs yellow-white. Reddish 
around eyes. Ends of fourth femora and patellae slightly red- 
dish. Abdomen with irregular gray marks, reddish around nip- 
ples, on each lateral projection and on posterior. Anterior me- 
dian eyes larger than otliers, their diameter apart, almost touch- 
ing laterals. Posterior median eyes three-quarters diameter 
apart, one-quarter from laterals. A pair of horns between eyes. 
Abdomen snbtriangular with numerous dorsal nipples (Fig. 40). 
Total length 1.3 mm. Carapace 0.52 mm long. First femur, 1.00 
mm. Second patella and tibia, 0.70 nnn ; third, 0.47 mm: fourtli, 
0.75 mm. (The specimen described is damaged.) 



LEVI: AMEKICAX KIMSINUS 17 

Diagnosis. Like the related E. dominicus the abdomen lias nip- 
ples on the dorsum (Pig. 40). The eonneetinp: ducts wind once 
around the seminal receptacles (Fig. 41), wliilc tliose of E. 
dominicus are shorter and do not wind around. 

Episinus pyrus sp. n. 
Figures M-'M) 

Type. Female liolotype from Suininil, Panama Canal Zone, 
16-17 August 1950 (A. M. Chickering), in the Museum of Com- 
parative Zoology. The specific name is an arbitrary combination 
of letters. 

Description. Carapace yellow-white with a bright red median 
band (Fig. 34). Sternum yellow-white, legs yellow-white with 
distal end of femora and patellae dusky. Dorsum of abdomen 
mottled black but area around each nipple and lateral extension 
bright red (Fig. 34). A red patch on each side of abdomen. 
\'enter yellow-white. Carapace with two horns between anterior 
median eyes. Anterior median eyes slightly larger than poste- 
rior medians, much larger tlian laterals, laterals on tubercles. 
Anterior median eyes three-quarters diameter apart. Posterior 
median eyes one diameter apart, their radius from laterals. 
Total length 1.2 mm. Carapace 0.52 mm long, 0.52 mm wide. 
First femur, 0.96 nnn ; patella and tibia, 1.08 mm ; metatarsus, 
0.71 nun ; tarsus, 0.47 nun. Second patella and til)ia. 0.62 mm ; 
third. 0.47 mm; fourth, 0.78 mm. 

DicKjnosis. Like E. dotiii)iicus and E. iiioyohdiiiha tlie abdo- 
men has dorsal nipples (Fig. 34). The transverse lip of the 
epigynum (Fig. 36) separates E. pyrus from these related spe- 
cies. The connecting ducts are very short (Fig. 35). 

Records. Panama Canal Zone: Sunnnit Park, Dec. 1957, 9 
paratype (A. M. Chickering) ; Summit, 21-29 July 1950, 9 para- 
type (A. M. Chickering). 

Episinits colima Levi 

Kpi.'<inus colima Levi, 195.5, Jour. Now York Ent. Soc, 62: 76, figs. 11, 40, 
$. Male holotj'pe from Las Iluincflades, Ariiieiia, roliiiia, ^lexico, in 
the American Museum of Natural History. 

The abdomen, which is missing from the holotype specimen, 
has a narrow ring of l)lack broken by red arouiid the edge of the 
dorsum. The large tubercle in the center is red with a black 
spot anteriorly. Otherwise the coloi- is yellow-white. It is of 
the same shape as related species. 



18 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Distribution. Colima, Mexico, to Panama Canal Zone. 
Records. Panama Canal Zone: Barro Colorado Isl., 20 April, 
1953, $ (A. M. Nadler, AMNH). 

Episinus panamensis Levi 

Figures 37-39 

Episinus panamensis Levi, 1955, Jour. New York Ent. Soc, 62: 73, figs. 
14, 35, $ . Male holotype, from Barro Colorado Island, Panama Canal 
Zone, in the American Museum of Natural History. 

Description. Female pattern and coloration and general struc- 
ture like that of male. The abdomen has one median dorsal 
nipple (Fig. 37). Total length 1.9 mm. Carapace 0.72 mm long, 
0.65 mm wide. First femur, 1.62 mm ; patella and tibia, 1.72 
mm; metatarsus, 1.59 mm; tarsus, 0.60 mm. Second patella and 
tibia, 0.98 mm; third, 0.68 mm; fourth, 1.21 mm. 

Record. Panama Canal Zone: Barro Colorado Island (numer- 
ous records). 

Episinus vaticus sp. n. 
Figures 43-47 

Type. Male holotype from Forest Reserve, Panama Canal 
Zone, 4-6 July 1939 (A. M. Chickering), in the Museum of Com- 
parative Zoology. The specific name is an arbitrary combination 
of letters. 

Description. Carapace yellow with a dusky line. Sternum 
gray. Legs yellow with some dusky marks. Dorsum of abdomen 
with a large white spot having some black behind it and many 
small white spots; each lateral extension dark on posterior side, 
reddish anteriorly (Figs. 46, 47). Venter of abdomen light gray. 
Female similar except having much red pigment on carapace 
and abdomen. Two horns between anterior median eyes. Lat- 
eral eyes on tubercles. Anterior median eyes much larger than 
posterior medians. Anterior medians two-thirds their diameter 
apart. Posterior medians one diameter apart, their radius from 
laterals. Total length of female 1.9 mm. Carapace 0.73 mm long, 
0.68 mm wide. First femur, 1.69 mm; patella and tibia. 1.63 
mm; metatarsus, 1.72 mm; tarsus, 0.60 mm. Second patella and 
tibia, 1.04 mm; third, 0.62 mm; fourth, 1.33 mm. Total length 
of male 1.5 mm. Carapace 0.60 nun long, 0.57 nun wide. First 
femur, 1.54 mm; patella and tibia, 1.62 mm; metatarsus, 1.60 
mm; tarsus, 0.55 mm. Second patella and tibia, 0.91 mm; third, 
0.60 mm ; fourth, 1.17 mm. 



LEVI: AMERICAN EPISINUS 19 

Diagnosis. The male of this species is readily distiiijiiiislied 
hy the distal diagonal hook on the palpal coiiduetor (Fi<>'. 45). 
The epifjynuni depression has a median posterior septnin (Fig. 
44) and the connecting ducts are very short (Fig. 43), unlike 
other Central American species. The abdomen lacks dorsal nip- 
ples (Fig. 47). 

Records. Costa Rica: San Isidro del General, (iOO-l^OO m, S 
(D. Rounds). Panama Canal Zone: Forest licserve, 4-() .Inly, 
1939, 9 paratype (A. M. Chiekering). 

Episinus aspus sp. n. 
Figures 48-51 

Type. Male holotype from ^lusawas, Waspuc River, Nica- 
ragua, 30 Sept. 1955 (B. Malkin), in the American Museum of 
Natural Histor3^ The specific name is an arbitrary combination 
of letters. 

Description. Carapace yellow-white, dusky on sides. Eye re- 
gion reddish. Sternum gray. Legs yellow-white. Abdomen red- 
dish and black around border of dorsum ; center of dorsum 
with white pigment in male, without pigment in female ; venter 
reddish in female, dusky in male. Anterior median eyes seem- 
ingly larger than others, about one-third their diameter apart. 
Posterior median eyes less than one diameter apart, touching 
laterals. Pigment around base of lenses makes it difficult to see 
their exact shape. The females have horns between eyes, but 
these are absent in males. Abdomen subtriangular (Fig. 51), 
smooth, lacking nipples. Total length of female 2.2 mm. Cara- 
pace 0.71 mm long, 0.62 mm wide. First femur, 1.50 nnii ; pa- 
tella and tibia, 1.42 mm; metatarsus, 1.36 mm; tarsus. O.GO nnn. 
Second patella and tibia, 0.85 mm; third, 0.58 mm; fourth, 1.17 
mm. Total length of male 1.5 mm. Carapace 0.62 mm long, 0.55 
mm wide. First femur, 1.48 mm; patella and tibia, 1.59 mm; 
metatarsus, 1.32 mm. Second patella and tibia, 0.85 nun; thii-d, 
0.65 mm; fourth, 1.17 mm. 

Diagnosis. The distal margin of embolus l)ase is almost at 
right angles to the long axis of the palpus (Fig. 50), while it is 
diagonal in the related E. panamensis. The median anterior 
dark spot of the epigynum (Fig. 49) and the longer seminal 
receptacles and shorter connecting ducts (Fig. 48) distinguish 
females from E. panamensis. 

Record. One 9 paratype collect(Hl with holotype. 



20 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOCA' 

Episinus bimucronatus (Simon), new coml)ination 
Figures 52-54 
Spliyrotinus himncronaius Simon, 189-i, Histoire Naturelle des Araignees, 1: 
551, nomen nudum; 1894, Ann. ent. Soc. France, 64: 144. Female holo- 
type from San Esteban, [Aragua], Venezuela, in the Museum National 
d 'Histoire Naturelle, Paris, examined. 
Description. Carapace yellow-white with silvery pigment be- 
tween eyes and dark pigment behind anterior median eyes. 
Sternum, legs whitish-yellow. Abdomen with white pigment 
spots on dorsum and posterior (Fig. 54). No horns in eye re- 
gion. Diameter of anterior median eyes equal to radius of other 
eyes. Lateral eyes on tubercles. Anterior median eyes one and 
one-half diameters apart, almost touching laterals. Posterior 
median eyes one-third diameter apart, one-quarter diameter 
from laterals. Abdomen wider than long with a median anterior 
hump and two posteriorly directed humps (Fig. 54). Some 
stronger setae on dorsum of distal end of patellae and some on 
tibiae. Total length 1.4 mm. Carapace 0.54 mm long, 0.44 mm 
wide. First femur, 1.04 mm; patella and tibia, 1.00 mm; meta- 
tarsus, 0.84 mm ; tarsus, 0.40 mm. Second patella and tibia, 0.68 
mm ; third, 0.46 mm ; fourth, 0.76 mm. 

Episinus bicorniger (Simon), new coml)ination 
Figures 55-57 
Theridium hicorne Keyserling, 1891, Die Spinncn Amerikas, Brasilianisclio 
Spinnen, 3: 193, pi. 7, fig. 140, 9, $. Male and female syntypes from 
Serra Vermelha, [Est. Eio de Janeiro], Brazil, in the British Museum, 
examined. Not T. hicorne Wider. 
Janulus bieornigera Simon, 1894, Histoire Xnturelle des Araignees, 1: .IIT. 
New name for T. hicorne Keyserling. 
Abdomen subtriangular as related species. Total length of 
female 2.2 mm. Total length of male 1.7 mm. 

Episinus ji'arezi Levi 
Episinus juarczi Levi, 19.15, Jour. New York Ent. Soc, G2 : 74, figs. 5, 6, 
30, 31, 42, 43, 5, $. Male holotype from Tamaulipas, :Mexico, in tlie 
American Museum of Natural History. 
Distrihiitio'u. Tamaulipas, San Luis Potosi to Oaxaca, Mexieo. 

Episinus chiapensis Levi 
Episinus chiapensis Levi, 1955, Jour. New York Ent. Soc, 02 : 76, fig. 7, $ . 
Male holotype from Las Ruinas de Palenque, Chiapas, ^Mexico, in the 
American Museum of Natural History. 
Distribution. Known only from Chiapas, Mexico. 



LEVI: AMERICAN EI'ISINUS 21 

Efisinis nadleri Levi 

Episinus nadleri Levi, 1955, Jour. New York Eiit. Soc, ni2 : 77, fifjs. 12, 28, 
29, 37, 9, 6. Female holotype from Soiitli P.imiiii, Ualiama Isliiiids, 
in the American Museum of Natural Histoiv. 

Disiribi(tio)t. Bahaiiui Islands and Jamaica. 
Additional Record. •Jamaica: Tlic (ii-cal Morass, 25 Mai-cli 
1955, 6 (A. M. Nadler, AMXIl). 

Episinus nebulosus (Simon), new comliination 
Figures 64-68 

Janulus nchiilosns Simon, 1895, Ann. Soc-. ent. France, 64: 1.35. Female 
holotype from Serra de Communaty, Prov. Pernambuco, Brazil, in the 
Museum National d'Histoire Naturelle, Paris, examined. 

Janulus ffcrmaini Simon, 1895, ihid., 64: 136. Female holotype from Para- 
guay in the Museum National d'Histoire Naturelle, Paris, examined. 
NEW SYNONYMY. 

Note. Female holotype of ./. nebulosus has a label indicating 
that it comes from Sa. Communaty, an unknown location placed 
by Simon at times in the neighboring state of Ceara. 

Description. Carapace with sides brownish, darker than mid- 
dle. Sternum, legs yellow-brown ; ends of segments slightly 
darker. Abdomen with scattered fine black spots and some 
white pigment spots anteriorly on dorsum, between humps and 
around sides. Venter of abdomen gray, darker on sides than in 
middle. Two horns in eye region. Lateral and posterior eyes on 
tubercles. Abdomen about as wide as long (Fig. 67). Epigynum 
openings distinct (Fig. 66) ; two duct loops in ventral view if 
cleared and one loop visible in dorsal view of female genitalia 
(Figs. 64, 65). Total length 2.8 mm. Carapace 0.82 mm long, 
0.74 mm wade. First femur, 1.40 mm; patella and til)ia, 1.62 
mm; metatarsus, 1.36 mm; tarsus, 0.36 mm. Second patella and 
tibia, 0.86 mm; third, 0.64 mm; fourth, 1.12 mm. 

The holotype of J. germaini is a younger adult female still 
showing a dorsal abdominal pattern (Fig. 68). The epigynum 
and internal genitalia are like those of the holotype of J. )u'hu- 
losus. 

Episinus bicruciatits (Simon), new combination 
Figures 69-72 

Janulus hicruciatus Simon, 1895, Ann. Soc. ent. France, 64: 136. Female 
holotype from Mato Grosso, Brazil, in the :Mus('um National d'Histoire 
Naturelle, Paris, examined. 



22 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Description. The whole specimen j^ellow-white except some 
pigment behind anterior median eyes and silvery around other 
eyes. Abdomen with indistinct longitudinal gray band having 
two cross bands (Fig. 72), a black mark on venter above pedicel, 
a distinct round black spot on posterior side of each lateral tu- 
bercle and a white pigment line on each side of spinnerets out- 
side of which is a black mark. Horns between eyes large ; lat- 
eral and posterior median eyes on tubercles. Abdomen subtri- 
angular with tubercles more distinct from ventral view. Total 
length 2.6 mm. Carapace 0.76 mm long, 0.68 mm wide. First 
femur, 1.52 mm; patella and tibia, 1.60 mm; metatarsus, 1.50 
mm ; tarsus, 0.54 mm. Second patella and tibia, 0.84 mm ; third, 
0.62 mm; fourth, 1.14 mm. 

Episinus salobrensis (Simon), new combination 
Figures 73-78, Map 

Janulus salohrensis Simon, 1895, Aim. Soe. ent. France, 64: 135. Two fe- 
male syntypes from Salobro [near Vargito on old maps], Bahia, Brazil, 
in the Museum National d 'Histoire Naturelle, Paris, examined. 

Episinus erytlirophihalmus, — Levi, 1955, Jour. New York Ent. Soc, 62: 
74, figs. 24, 25, .36. Not E. erythroplithalmus (Simon). 

Description. The two type specimens are almost colorless yel- 
lowish, the only pigment being silvery behind eyes ; sides of 
carapace sliglitly darker than middle. Posterior sides of abdo- 
men slightly reddish, some small white pigment spots, and a larger 
white spot on each side of spinnerets. Horns between eyes small ; 
lenses of lateral and posterior median eyes on tubercles. Abdo- 
men subtriangular (Fig. 77). Total length of one female syn- 
type 2.0 mm. Carapace 0.80 mm long, 0.70 mm wide. Legs 
broken off. 

Figures 73-75 and 77 were prepared from a syntype. 

The female has been described previously (Levi, 1955). The 
anterior lateral margins of the oval depression of the epigynum 
are more or less sclerotized. Although the specimen previously 
described had red eyes, no others seen have red ])igment in the 
eye region. Only fragments of males collected with females were 
available. 

Records. Lesser Antilles. Trinidad: Simla near Arima, 12 
Dec. 1954, ? ; 28 Dec. 1954, 9 (A. M. Nadler, AMNH) ; Port 
of Spain, 1913, 9 (R. Thaxter). Britisli Guinna: Kuyuwdni 
Landing, Kuyuwini River, 20 Nov. 1937, 9 . $ fragments (W. 
G. Hassler, AMNH). Brazil. Pernamhuco: Recife (SMF). 



LEVI: AMEKICAX KIMSIXUS 23 

EpISINUS ZURLl'S sp. 11. 

Fi<>'iires 58-63 

Type. Male holotype from Venezuela (E. Simon) in llie 
Museum National d'llistoire Naturelle, Paris (no. 13029). Tlie 
name is an arbitrary combination of letters. 

Note. Altliough it is poor praetiee to describe new species 
witliout accurate locality data, 1 liave done so here liecanse a 
niiiiibci- of specimens, both male and fcnialt', ai-c a\ailabl('. Also, 
it is known that Simon, who collected tlie six'ciniens, travelled 
in only a small region of Venezuela : from the Caracas vicinity 
to Tovar, Arapua, to Valencia, Puerto Cabello and San Esteban, 
Carabobo. The specimens were in the Paris collections, mixed 
up with specimens of E. eryihrophfJialinuH and labelled as such. 

Description. Carapace yellow-white, some pigment behind an- 
terior median eyes, silvery between other eyes, sternum, legs 
yellow-white. Abdomen posteriorly and sides gray, center of 
dorsum with white pigment spots and .some gray pigment ; ven- 
ter light gray, darker toward sides. Carapace witii relatively 
small horns between eyes (Fig. 62). Anterior median eyes much 
larger than lenses of other eyes, which are on tubercles. Ab- 
domen without dorsal nipples (Fig. 62). Total length of fe- 
males 2.5 mm. Carapace 0.68 mm long, 0.64 mm wide. First 
femur, 1.56 mm; patella and tibia, 1.44 mm; metatarsus, 0.86 
mm; tarsus, 0.42 mm. Second patella and tibia, 0.84 mm; third, 
0.60 mm; fourth, 1.04 mm. Total length of male 1.6 mm. Cara- 
pace 0.62 mm long, 0.56 mm wide. First femur, 1.52 mm ; pa- 
tella and til)ia, 1.56 mm; metatarsus, 1.36 mm; tarsus, 0.56 mm. 
Second patella and tibia, 0.84 mm; third, 0.62 mm; fourth, 1.08 
mm. 

DiaejnosiH. The connecting ducts lead posteriorly from the 
openings (Figs. 58-61) unlike the similar E. erythrophtlKilmvx. 
The transverse line between the openings is sometimes more 
anterior, sometimes more posterior, in different specimens (Figs. 
60, 61). The males are distinguished from E. erythrophthalmns 
by the basal flare of the conductor, which projects ventrally, is 
sclerotized, and has small teeth on the margin (Fig. 63). 

Records. Male and female paraty]ies collected with holotype. 

Episinus ERYTiiROPirriiAi..Mrs (Simon) 

Figures 79-93, Map 

Januhi.t erythrophthaJmus Simon, 189-4, t'roc. Zool. Soc. Londori, p. 525. 
IMale and female syntypes from St. Vincent Island, Lesser Antilles, in 
the British Museum, examined. Not E. erythrnphthalmvfi, — Levi, 1955. 



24 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Description. Specimens from Panama. Carapace j^ellowish 
with dusky border and dusky patches on each side. Sternum 
white. Legs yellowish with dusky marks. Dorsum of abdomen 
black behind and on sides ; light central area with white spots 
(Figs. 86, 89). Venter with epigastric area gray and black 
patches on sides that are extensions of the lateral and posterior 
dorsal black areas. Female generally lighter and less distinctly 
marked than male ; white spots more numerous and smaller, but 
also usually having the four dark marks on venter. Two horns 
between eyes. Anterior median eyes much larger than others. 
Posterior and lateral eyes on tubercles. Total length of female 
2.00 mm. Carapace 0.62 mm long, 0.62 mm wide. First femur, 
1.32 mm; patella and tibia, 1.44 mm; metatarsus, 1.28 mm; tar- 
sus, 0.44 mm. Second patella and tibia, 0.78 mm ; third, 0.54 mm ; 
fourth, 0.98 mm. Total length of male 1.5 mm. Carapace 0.59 
mm long, 0.55 mm wide. First femur, 1.32 mm; patella and tibia, 
1.47 mm; metatarsus, 1.28 mm; tarsus, 0.47 mm. Second patella 
and tibia, 1.02 mm; third, 0.52 mm; fourth 1.04 mm. 

Figures 80, 81, 90 were prepared from the syntypes. 

Note. This species, apparently widespread and relatively 
common, is quite variable. At first it was thought that the speci- 
mens coming from Panama belong to three species ; l)ut, on care- 
ful comparison, they were all found to have the same propor- 
tions and only superficial differences in the epigynum and pal- 
pus. The seminal receptacles and more sclerotized parts of the 
palpus are similar. The differences seem to be due to different 
degrees of transparency of the epigynum and the position of 
the anterior transverse sclerotized piece (Figs. 81, 83, 85). The 
transparent palpal sclerites seem to be in slightly different posi- 
tions in each individual (Figs. 90-93). 

Distrihution. Panama to Bolivia. 

Records. Panama. Arraijan (A. M. Chickering) ; 8 km S of 
El Valle (A. M. Chickering). Panama Canal Zone. Forest Re- 
serve ; Madden Dam ; Chilibre ; Summit ; Balboa ; 3 km N of 
Paraiso (all A. M. Chickering). Lesser Antilles. Tohago Isl. 
(P. H. Johnson, BMNII). Triinelad: Simla near Arima (A. M. 
Nadler, AMNH). Piarco (A. M. Nadler, AMNH). Venezuela. 
9, $ (E. Simon, MNHN). /)/.^^ Ffrf.; Caracas. 1887-1888, $ 
(E. Simon, MNHN). Ara<jua: Maracay (A. M. Nadler, AMNH). 
British Guiana. Kuyuwini Landing, Kuyuwini TJiver (W. G. 
Hassler, AMNH). Bolivia. Cochahawha : El Palmar. Cbapare, 
900-1000 m, Sept. 1956, £ (L. Pena, ISNB). 



LEVI : AMERICAN El'ISINUS 25 

Index 

Valid names are printed in italies. Patre luinibers i-efer to main 
referenees. 



iigrcste, 111 
alhost rial IIS, I'l 
niiu'i-icMiius, .") 
amocnuH, 14 
as pus, 1!) 
l)ic-onie, 20 
hicornlf/cr, 20 
hicruciatus, 21 
bigibbosus, 9 
biiniicronatus, 20 
hitiil)erc-iilatum, 8 
brasiliaiuis, 5 
hruncoviridis, 11 
cliiapcnsis, 20 
Clementina, 13 
cognatus, 13 
colima, 17 
dominicus, 15 
(lusenii, 10 
email IIS, 11 
L'rytlirophtlialinus, 22 



erytlir<i]ililliahiuts, 23 
SiM'niaini, 2 1 
gratiosus, 13 
iin m undus, 8 
im plexus, 15 
juarczi, 20 
longipes, 13 
malacliinns, 14 
moi/obaniha, 16 
nadlcri, 21 
nebidosus, 21 
panamensis, 18 
;;]//•;/*•, 17 
recifensis, 8 
salobrensis, 22 
simplifrons, 13 
teresopoUs, 15 
truncatus, 5 
typicus, 10 
unit us, 16 
vatieus, 18 



zurlus, 23 



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Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. 181, No. 2 



FOSSIL MAMMALS FROM THE LOWER PLIOOENE OF 
FISH LAKE VALLEY, NEVADA 

By 

John B. Clark, Mary R. Dawson aiul Albert E. Wood 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

March 30, 1964 



Publications Issued by or in Connection 

WITH THE 

MUSEUM OP COMPARATIVE ZOOLOGY 
AT HARVARD COLLEGE 



Bulletin (octavo) 1863 ■ — The current volume is Vol. 131. 

Breviora (octavo) 1952 — No. 199 is current. 

Memoirs (quarto) 1864-1938 — Publication was terminated with 
\^ol. 55. 

JoHNSONiA (quarto) 1941 — A publication of the Department of 
Mollusks. Vol. 4, no. 41 is current. 

Occasional Papers of the Department op Mollusks (octavo) 
1945 — Vol. 2, no. 28 is current. 

Proceedings of the New England Zoological Club (octavo) 
1899-1948 — Published in connection with the Museum. Publication 
terminated with Vol. 24. 

The continuing publications are issued at irregular intervals in num- 
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obtained from the Publications Office of the Museum of Comparative 
Zoologv, Cambridge 38, IMassachusetts. 



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are out of print ; volumes 3, 5, 7, 9, and 15 are sold by the Museum, and 
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The Proceedings of the First International Symposium on Natural 
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may be had upon request. 



Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. 131, No. 2 



FOSSIL iMAMMALS FROM THE LOWER PLIOCENE OF 
FISH LAKE VALLEY, NEVADA 

By 

John B. Clark, Mary R. Dawsox and Albert E. Wood 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

March, 1964 



Bull. Mus. Coiiii). Zoo)., Ilarvnr.l riiiv., 131 (2) : 27-63, ^rnrcli, 1964 

No. 2 — Fossil Mammals from the Lower Pliocene of Fish Lake 

Valley, Nevada 

By John I>. ("lark/ .Makv II. Dawson- a.n'd Ai.bkkt E. Wooo^ 

INTRODUCTION 

The material on which this study is based was collected by 
Wood, in 1935, from Hall's locality A (1930c, pi. 37, fi». 1) in the 
early Pliocene Fish Lake Valk^y bods, Esmeralda Formation, 
seven miles north of Arlemoiit, Nevada. 

The material formed the basis for tlie unpublished Master's 
thesis, submitted to Amherst College, by Clark. In subsequent 
years it has proven impossible for him to complete the paper for 
publication, and the material has now been reworked by Dawson 
and Wood. Wood has brought up to date and revised Clark's 
manuscript for the rodents, and Dawson has done the same for 
the other forms. 

The authors are grateful to Di's. J. T. Gregory, Donald Savage 
and R. A. Stirton for the loan of specimens ; to Mrs. Katherine 
M. Reed and Drs. Claude Hibbard and Peter Robinson for dis- 
cussions ; and to Mrs. Frances W. Wood for critical reading and 
other assistance in preparation of the manuscript. Figures 6 and 
7, B, C and D were drawn by Dr. Florence D. Wood. The 
material was collected while Wood was Cutting Traveling Fellow 
in Columbia University. The study has been assisted by the 
Dorothy Bridgman Atkinson Fellowship of the American Asso- 
ciation of University Women awarded to Dawson, and by grants 
from the National Science Foundation and the Marsh Fund of the 
National Academy of Sciences to Wood. Abbreviations used are : 
M.C.Z., Museum of Comparative Zoology; S.D.S.M., South 
Dakota School of Mines and Technology; U. Cal., University of 
California Museum of Paleontology. We are grateful to the 
Museum of Comparative Zoology for undertaking the publication 
of this paper. 



1 Biology Department, Marietta Collego, Maiiotta, Ohio. 

2 Carnegie Museum, Pittsbur^'li, rennsylvaiiia. 

3 r.iology Department, Amherst College, Amherst, Massachusetts. 



30 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



Order INSECTIVORA 

Family TALPIDAE 

DoMNiNoiDES cf. BiPARENsis Greeii, 1956 

Figure 1 

Material: M.C.Z. Nos. 17887, incomplete left lower jaw having 
Ml, M2-M3 (broken), alveoli of P4 ; 17888, incomplete left 
lower jaw having Mo, alveoli of P4, Mj, M3 ; 17889, left M2 
(broken). 

In size (Table 1) and in most general characteristics these 
specimens resemble the type and only previously reported speci- 
men of Domninoides riparejisis, S.D.S.M. No. 53170, from the 
Clarendonian Wolf Creek faunule of South Dakota (Green, 
1956, pp. 152-154). Compared to teeth in the type specimen, 
M.C.Z. No. 17889 is less worn, M.C.Z. No. 17887 is slightly more 
worn, and M.C.Z. No. 17888 is much more w^orn. 




Fig. 1. Domninoides cf. riparen.tis. T.ateial view of left lower jaw, M.C.Z. 
No. 17887, X 9. 



The most distinct difference from the type specimen is exhibited 
by M.C.Z. No. 17887 (Fig. 1), which has on Mj a small but dis- 
tinct anterior cingulum that connects to the anterolingual cuspule. 
The anterior wall of M^ in the type is smoothly convex, lacking 
a cingulum. Another difference appears on M3 in M.C.Z. No. 
17887, which has an anterior cingulum that is more reduced 
buceally than in S.D.S.M. No. 53170. Also, in the type specimen 
the metastylid of Mj is larger than that of Mo, whereas in 
M.C.Z. No. 17887 the metastylid of Mo is prominent and a distinct 
metastylid is absent on Mj. 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 'M 

The taxonomie !si<;nitieaiicc' o£ these dift'erenees is questionable 
in light of the few available specimens. Possibly the variation 
in the anterior wall of jM^ is a matter of individual diversity. 
Somewhat similar individual variation has been rei)orted in 
another fossil talpid, Mesoscalops scopclotcnws, in which there 
is "variable development of a small anterior einpulum, wliieh 
appears in the majority of specimens" (Reed, 1960, p. 4). That 
the size of the anterior cingulum may vary with wear in the 
Fish Lake Valley talpid is shown by the fact that the cingulum 
on the well worn M2 of M.C.Z. No. 17888 is narrower than that 
of M.C.Z. No. 17887. Similarly, stage of wear could account for 
the difference between the type and M.C.Z. No. 17887 in the 
cingulum of M3. 

Since wear and individual variation are perhaps responsible 
for the differences between the Fish Lake Valley talpid and the 
type of D. riparensis, a definite specific assignment should wait 
until more specimens allow better estimation of the range of 
variation in either population. 

Variation that can be recognized as individual is exhibited by 
the two jaws from Fish Lake Valley, which differ from one an- 
other in the position of the two mental foramina. In both jaws, as 
in the type, the anterior foramen is below P;. . One specimen, 
M.C.Z.No. 17888, resembles the type in having the more posterior 
foramen in line with the posterior wall of the alveolus of P4, 
whereas ]\LC.Z. No. 17887 has the posterior foramen farther 
forward, in line with tlie middle of P4. 

Table 1 
Measurements (in niillinieteis) of Domninoidrs ef. riparcufsis 





M.C.Z. No. 17 


887 


M.C.Z. 


No. 17888 


JNT] length 


ca. 2.3 









width tiigonid 


1.4 






— 


Avidth talonid 


1.7 






— 


Mo length 


— 






2.4 


width trigonid 


1.7 






1.7 


width talonid 


— 






1.6 



alveolar length Mi-M;i ca. 6.5 6.1 

outside depth jaw, at middle of Mi 2.2 2.1 



32 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Order ?INSECTIVORA 

Figure 2 

A toothless fragment of a left lower jaw, M.C.Z. No. 17900 
(Fig. 2), represents an unidentifiable species of small mammal. 
The alveoli of the penultimate tooth, wdth the anterior wall 
broken away, and of the last tooth indicate that the penultimate 
tooth was somewhat larger than the last. The alveolus of the last 
tooth is 1.4 mm long. The alveolus for the root of the trigonid 
of the last tooth is set obliquely to the long axis of the jaw, 
directed anterolingually to posterobuecally, and is longer on the 
lingual side. The alveolus for the root of the corresponding tal- 
onid is longer anteroposteriorly and narrOAver transversely than 
that of the trigonid. The wall between the two alveoli of the last 
tooth has an indistinct, shallow groove dorsally, and that between 
the two alveoli of the penultimate tooth is more distinctly 
grooved. The deep masseteric fossa is bounded anteriorly by a 
rounded ridge. Lingually the surface of the jaw is essentially 
smooth ; a dental foramen occurs near the posterior edge of the 
incomplete specimen. Below the last tooth, the jaw is 1.5 mm 
deep. 




Fig. 2. ?Insectivore. Lateral view of left lower jaw fragment, INI.C.Z. 
No. 17900, X 8. 



Compared to other known members of the Fish Lake Valley 
fauna, M.C.Z. No. 17900 shows closest resemblance to Mystiptcrus 
vespertilio, the type and only reported specimen of which is a 
broken fragment of a jaw with Mo (IT. Cal. No. 29604). In both 
there is a deep masseteric fossa, and lingually both jaw frag- 
ments are essentially smooth. The toothless jaw is a little larger 
than the type of Mystipterus vespertilio and seems to have the 
anterior border of the ascending ramus relatively farther from 
the last tooth. The specimens are too incomplete to allow more 
than partial comparisons, and M.C.Z. No. 17900 is regarded as 
indeterminate. 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 33 

In the course of tliese comparisons the question arose again of 
tlie taxonomic assignment of Mystipterus, originally described 
as a vespertilionid bat and compared with Minioi)tcrus by Hall 
(1930a, p. 319). Ke-examination of the characters of Mysiipterus 
and of the differences from Miniopterus led Patterson and Mc- 
Grew (1937, pp. 256-257) to assign the former to the insectivore 
family Soricidae. The features of Mystiptcrus cited by Patterson 
and McGrew as characteristic of soricids occur in some othei- 
insectivores as well. The deep masseteric fossa, for exam]ilo, is 
found also in Xycfitlifriu))}, Micro ptcrnodus (Matthew, 1909. pi. 
51, fig. 1), and a geolabidine insectivore, cf. Myolcstcs dasypclix 
(McKenna, 1960, p. 147). The combination of characters known 
in Mystipterus may not preclude reference to the Sorieidae, but 
at the same time they do not seem to make such a reference the 
only assignment possible. It would seem necessary to have speci- 
mens of Mystiptcrus in addition to the rather inadequate type in 
order to clarify the taxonomic position of the genus. 

Order LAGOMORPHA 

Family OCIIOTONIDAE 

HeSPEROLAGOMYS"' new genus 

Type species: Hcspcrolagomys fjalhreathi n. sp. 

Diagnosis: Cheek teeth hypsodont but rooted; occlusal surface 
of P^'-Mi with persistent crescentic valley, hypostria extending 
almost to crescent, and anteroloph transversely wider than 
posteroloph ; P^ with buccal fold between trigonid and talonid, 
anterointernal groove in trigonid, lingual wall short anteroposter- 
iorly ; trigonid of P4-M2 wider and shorter than talonid, talonid 
with anterior protrusion directed toward trigonid, and postero- 
lophid present in early stage of wear ; large mental foramen below 
P3, smaller mental foramina anterior to P3 and in line between 
M1-M2 ; lower teeth include M1-M3 ; size near that of Orcolagus 
nevadensis; tooth measurements a.s given in Table 2. 

HeSPEROLAGOMYS GALBREATIir'' U. sp. 

Figures 3-4 

Type: M.C.Z. No. 17890, incomplete right lower jaw with 
broken incisor, P3-M2, and alveolus of M3. 



4 Pr()iii (Jrci'k : hcspcros — wi'st : Iih/ok — Iimpc; iii/m — iiidusc. 

o For Dr. E. ('. Galbreath in r('(oj,'niticiii ol" his wurk (ni fossil lagoiiioriihs. 



34 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



Hypodigm: Type; M.C.Z. Nos. 17891, fragmentary left lower 
jaw with P3-M2 ; 17892, fragmentary left lower jaw with talonid 
of P4 to M2 ; 17893-17894, upper incisors ; 17895-17899, isolated 
upper cheek teeth; 7651-7652, isolated lower cheek teeth. Prob- 
ably referable, U. Cal. No. 29633, upper deciduous premolar. 

Diagnosis: As for the genus. 

Description: The skull, with the exception of a maxillary frag- 
ment, is unknown, and the upper dentition is represented by 
isolated teeth only. The anterior upper incisor has a longitudinal 
groove slightly medial of center on its anterior surface. The 
part of the incisor medial to the groove protrudes farther anter- 
iorly than does the lateral part. Of the upper cheek teeth, P- 
and P^ are not known, but P^ and probably JVP are represented. 
Unilateral hypsodonty is exhibited by these teeth, which are 
convex lingually (Fig. 3 A, C, D). Two small buccal roots and 
a larger lingual root are present on the knowai upper cheek 
teeth. 




Pig. 3. Hesperolagomys galhreathi, 11. gen., n. sp. Upper rheek teeth, 
X 9. Probable Ml, M.C.Z. No. 17898; A, anterior view; B, occlusal view. 
P4, M.C.Z. No. 17896; C, anterior view; D, occlusal view. 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 35 

On a worn P^, ^IX'.Z. Xo. ITcSf)."), the anterior lopli is wider 
than tlie posterioi- h)ph. The pattern on the occlusal surface 
includes an isolated, cement-filled, creseentie valley in the buccal 
half of the tooth and a cenient-lilled internal hypostria. The 
hypostria is directed toward the anterior wall of the crescent and 
extends almost to its lingual wall. Features of the buccal edge of 
the occlusal surface cannot be determined due to breakage. 
Another specimen, M.C.Z. No. 17896 (Fig. :i C, D), seems to 
be a relatively unworn P^. At the occlusal surface the anterior 
and j)osterior lophs are nearly equal in width, but farther down 
the shaft the anterior loph protrudes more medially. A central 
lobe connects to the buccal wall between two rounded cuspules 
and extends in a wide V to join the posterior wall of the tooth. 
Anterior, lingual, and posterolingual to the central lobe is the 
cement-filled depression that forms the creseentie valley of the 
more worn tooth. Posterobuecal to the lobe is a second cement- 
filled depression. The buccal exits of these depressions are 
blocked by the buccal cuspules. The internal hypostria crosses 
about one-third of the occlusal surface. 

A worn tooth, M.C.Z. No. 17898 (Fig. 3 A, B), probably is a 
molar. In this specimen the anterior loph protrudes farther 
lingually than the posterior loph ; the complete width of the 
anterior loph is not shown, owing to its broken lingual wall. The 
creseentie valley divides anterobuccally into tw'O distinet parts 
around a transversely elongated cuspule. The aiiterobuccal part 
of the vallej' seems to be better developed than in M.C.Z. No. 
17895, a P"* in an approximately comparable stage of w^ear. The 
probable molar lacks the posterobuecal cuspule and is reduced 
posterobuecall.y in comparison with M.C.Z. No. 1781)6, although 
valid comparisons with the latter are limited by differences in 
stage of wear. Interpretation of M.C.Z. No. 17898 as a molar 
is supported by comparisons w'ith Amphilagus fontannesi, a late 
Miocene oehotonid in which M^ reseml^les this probable molar and 
P'l is more similar to M.C.Z. No. 17896. The closer resemblance of 
M.C.Z. No. 17898 to M^ than to M^ of A. fontannesi suggests 
that it may be the anterior molar, since M^ is more reduced 
posteriorly in A. fontannesi (Forsyth Major, 1899, pi. 36, figs. 
6 of M-, 7 of Ml, 8 of P^). 

An isolated upper tooth, U. Cal. No. 29633, was tentatively 
identified as Entoptychusf sp. (Hall, 1930c, p. 296) but was 
subsequently recognized as a deciduous premolar of a lagomorph 
(Wood, 1936c, p. 25). The tooth is smaller than the permanent 



36 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



upper teeth of Hesperolagoruys, but probably represents this 
ochotonid rather than the much larger leporid of the Fish Lake 
Valley fauna. 

The lower jaw and dentition are more adequately represented 
than the upper. The ventral border of the horizontal ramus (Fig. 
4 B) is essentially straight below the cheek teeth and curves up, 
below the diastema. The jaw is slightly deeper below the posterior 
than below the anterior cheek teeth. The shape of the jaw is 
more similar to that in Titanomys and Oreolagus than to that 
in Ochotona, in which the jaw is deeper below the anterior cheek 
teeth and has a more concave dorsal border at the diastema. 





Fig. 4. Hespcrolagomys galhrcaflti, ii. gen., ii. sp. Right lower ^aw with 
P;rM2, type, M.C.Z. No. 17890, X 6- A, oeelnsal view of cheek teeth; B, 
lateral view. 



On the lateral surface of the jaw are several mental foramina ; 
the largest of these is in line with the talonid of P3 and below 
mid-depth of the jaw. A smaller foramen occurs anterior to P3, 
above mid-depth, and a depression with two small foramina is 
situated in a line between Mi and Mo and lower than the anterior 
foramina. This disposition of mental foramina, with the middle 
foramen the largest, differentiates Hespcrolagomys from other 
known ochotonids. In Desrnatolagus vetustus, D. gohiensis, and 
SinolagomyH (Bohlin, 1942, pp. 62-63), anterior and posterior 



CLARK, DAWSON. WOOD: FOSSIL MAMMALS OF NEVADA 37 

mental loramina are present. Between them there occurs in some 
specimens another small foramen or foramina approximately in 
the position of the large foramen in TlesperoJagomys. Presence 
of a series of mental foramina seems to be primitive for lago- 
morphs. Different ochotonids retain and emphasize different 
foramina of this series. Hesperolagonnjs retains a primitive 
series, with emphasis on the middle foramen. Another variant 
on these foramina in an ocliolonid is seen in KcnjjalafjfJinijs of 
the Miocene of Africa, in which the two main mental foramina 
(Maelnnes, 1953, p. 10) seem to correspond to the middle and 
posterior foramina of Hcspcrolagninys. In Ochotona the single 
mental foramen, probably representing the posterior foi-amen of 
Hesperulagomys, is situated below M2. 

The shaft of the incisor extends approximately to a line below 
the middle of Mj, as indicated by a swelling on the medial surface 
of the jaw. The lower cheek teeth are hypsodont but rooted. 
For most of their length the trigonid and talonid of P4-M2 are 
connected by cement only, but a short distance above tlie roots 
the dentine of the two columns becomes confluent. An isolated 
tooth, probably a molar, shows two small rootlets for the trigonid 
and a single root for the talonid. The alveolar portions of P-; 
and P4 are relatively straight anteroposteriorly and extend down 
lateral to the shaft of the incisor. The lateral surface of the jaw 
swells out over P4, thus giving space for that tooth lateral to the 
incisor. The alveolar portions of M| and M2 curve posteriorly 
and in this way avoid interfering with the shaft of the incisor. 

The most complete lower jaw is the type specimen, M.C.Z. No. 
17890 (Fig. 4). On P3 a cement-filled buccal fold crosses about 
half the occlusal surface and marks the division between ti-igonid 
and talonid. The trigonid is rounded anterobuceally. Antero- 
lingually, P3 has a wide, shallow groove with a thin coating of 
cement. This groove is interpreted here as being in the ti'igonid, 
and not between trigonid and talonid. The lingual wall of P3 
is short anteroposteriorly. 

The trig'onids of P4-M2 are wider transversely and shorter 
anteroposteriorly than the corresponding talonids. Each talonid 
sends forward a narrow protrusion. Enamel is prominent on 
the external and posterior walls of trigonids and talonids. The 
alveolus of M3 is rounded buccally and is narrower transversely 
than that of the talonid of M2. The shape of the alveolus suggests 
that Mo was probably more rounded and less tapered buccally 
than is that tooth in Ochotona. 



38 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



A young individual of Hesperolagomys is represented by IT. 
Cal. No. 29626, an incomplete lower jaw with P4-M1 (Hall, 
1930c, p. 311 ; the specimen was tentatively identified hy Hall as 
Sylvilagusl sp.)- Small posterolophids, which would be worn 
away a short distance down the tooth, occur on the talonids of the 
two teeth. The limited hypsodonty of Hesperolagomys is illus- 
trated by this specimen, in which the little worn P4 shows at its 
base the confluence of the dentine of the columns that occurs just 
above the roots. 

Table 2 

Measurements (in millimeters) of Hesperolagomys galbreathi 





M.C.Z. 


M.C.Z. 


M.C.Z. 




No 


. 17895 


No. 17896 


No. 17898 






P-i 


pi 


probably Mi 


length 




1.5 


1.5 


1.3 


width anteroloph 




— 


2.3 


2,9 


width posteroloph 




— 


2.2 


2.5 




M.C.Z. 


No. 17890 








type 


specimen 






P3 length 




1.1 






width 




1.2 






P-i length 




1.7 






width trigonid 




1.9 






width talonid 




1.4 






Ml leugtli 




1.6 






widtli trigonid 




1.8 






width talonid 




1.4 






M2 length 




1.6 






width trigonid 




1.7 






width talonid 




1.4 






alveolar length Ps-Mj 




8.1 






length P3-M2 




5.8 






length P4-M2 




4.9 






inside depth jaw, at 










middle of Mi 




5.3 







Hesperolagomys is an ochotonid that retained into the early 
Pliocene a number of primitive characteristics, among which are 
the rooted cheek teeth, persistence of folds in the buccal part 
of the occlusal surface of P^ and j\P, and talonids that are nar- 
I'ower transversely than the trigonids on P4-M2. Combined with 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA '.]9 

these primitive characteristics, Hcspcrolagomys exhibits its own 
peculiar features, including the marked anterior protrusion of 
the talonids on P4-M0 and the disposition of the mental foramina. 

Other ochotonids that have been reported from the North 
American later Tertiary are OrcologKs from the Miocene and 
Ochotona whicli first appears in the middle Pliocene. Among the 
characters distinguishing Oreolagus from Hesperolagomys are, 
in the former, higher crowned cheek teeth, shape and proportions 
of the lower cheek teeth, in wliich the trigonids and talonids of 
P4-M2 are more nearly equivalent in width, and absence of M3. 
Ochotona is distinguished from Hesperolagomys by its more 
hypsodont cheek teeth, absence of a persistent crescentic valley 
on P-* and ]\P, more complex folds on P^, and approximately 
equivalent width of the columns of P4-M2. The presence of 
Hesperolagomys with its primitive characteristics in the North 
American early Pliocene seems to be a parallel to the presence 
oi Amphilagus fonfannesi, an ochotonid likewise having primitive 
dental features, in the late Miocene of Europe. 

Unless there has been a reversal of evolution aifecting several 
characteristics, which seems unlikely, Hesperolagomys was de- 
rived from a primitive ochotonid. Of known forms, Desniaiolagus, 
which has rooted cheek teeth and a generally primitive level of 
development, could be near the ancestry of Hesperolagomys. 
More specific evidence for such an affinity, other than the merely 
primitive features, is afforded by the structure of P.3. In 
Hesperolagomys that tooth has a narrow lingual exposure and an 
anterointernal groove that seems to be in the trigonid. Desma- 
tolagus gohiensis of the late Oligocene of Asia has a somewhat 
similarly shaped P3 in some individuals ; in late stages of wear 
the anterointernal groove is worn away in that species. An earlier 
species, D. vetustus of the Mongolian early Oligocene, shows the 
same general pattern of folding on P3, but the lingual wall is 
less reduced anteroposteriorly than in D. gohiensis (Burke, 1941, 
pp. 16-17) and Hesperolagomys. A trigonid of Po, that is divided 
by an anterior fold, and an internal wall of P3, that becomes 
reduced in later species, are among the characters distinctive of 
Burke's " Desmatolagus phylum" (1941, pp. 17, 22). If the 
folds on P3 in Hesperolagomys have been interpreted correctly, 
the similar structure of that tooth would seem to indicate affinity 
with Desmatolagus. Whether Hesperolagomys is clo.ser to Asian 
species of Desmatolagus or to North American species referred 
to that genus remains to be determined. 



40 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Family LEPORIDAE 
Hypolagus fontinalis Dawson, 1958 

Material: M.C.Z. Nos. 7640, incomplete left lower jaw with 
P4-M2 ; 7641, left premaxilla with upper incisors; 7642, isolated 
teeth ; 7643, postcranial fragments including proximal and distal 
ends of humerus, astragali, ealcanea, navicular. 

Hypolagus fontinalis, a previously known member of the Pish 
Lake Valley fauna (Dawson, 1958, p. 48), is represented by these 
specimens. Lower cheek teeth agree in size (Table 3) and struc- 
ture with other specimens of this species. 

The upper cheek teeth of H. fontinalis were previously un- 
known. Two folds, of which the lingual is longer, occur on the 
anterior surface of P-. The internal hypostria crosses somewhat 
more than half the width of the occlusal surface on P^-M^. The 
walls of the hypostria are strongly crenulated on P^; on speci- 
mens that are probably P"* or M^ the walls are less strongly 
crenulated ; and in a specimen that seems to represent M- the 
walls are only slightly wavy. Thus, the folding in the walls of 
the hypostriae decreases posteriorly in the series of molariform 
teeth. In general structure the upper cheek teeth resemble those 
of H. vetus, a species averaging larger in size than H. fontinalis. 

Table 3 
Measurements (in millimeters) of Hypolagus foniinalis 





M.C.Z. 

No. 7642 


M.C.Z. 
No. 7640 


M.C.Z. 
No. 7643 


P2 length 
width 


1.2 
2.6 






P4 or Ml length 
width anteroloph 
width posteroloph 


2.3 

4.2 
4.0 






P3 length 

width trigonid 
width talonid 


2.6 
2.0 
2.5 






P4-M2 length 




7.4 





astragalus, length proximodistal 10.6 

width 5.4 

humerus, length proximal end 10.9 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OK NEVADA 41 

Tlie posteranial parts are smaller than eorrespoiidinf? parts 
of //. vctus but suggest similarity to H. vetus in general level of 
development. 

Order RODENTIA 

Family ('K1("HT11)AE 
COPEMYS AVood M)W 

Type species: Hesperomys loxodon Cope 1874. 

Referred species: C. dcntalis (Hall), C. longidens (Hall), C. 
kfJIoggae (Ploffmeister), and C. esnieralelensis n. sp. 

Distribution: Late Miocene Barstow and Niobrara River to 
early Pliocene Fish Lake Valley; Nebraska, New Mexico, Cali- 
fornia and Nevada. 

Emended diagnosis: Cricetid in which alternation of buccal 
and lingual cusps has begun to develop; crowns low; no distinct 
mesocone or mesoconid, although mesoloph or mesolophid may 
be well developed ; protoconid and metaconid of Mi unite, after 
varying amounts of wear, at anterior end of protoconid ; meta- 
conid of M.).;j at anterior margin of tooth, with anterior cingulum 
absent or restricted to buccal margin of tooth; paracone of M^ 
unites with posterior end of protocone and, sometimes, with 
its anterior end; metacone of M^ unites with posteroloph rather 
than with hypocone; metacone of M- tending to unite in this 
manner ; lower incisors broad ; mental foramen l)elow or just 
in front of Mj ; masseteric fossa prominent, ending below Mj ; 
deep valley between M.^ and the coronoid process. 

One of the striking peculiarities of North American Tertiary 
rodent history is the record of the cricetids. In the middle Oligo- 
cene, Ewmys is unquestionably the most abundant rodent, and 
a number of different species have been recognized. Leidymys 
and Scottimus have developed from a Eumys ancestry. Species 
of Eumys are known from the Oligocene of the Great Plains 
(Wood, 1937; Galbreath, 1953) and of Montana (Wood, 1937, 
p. 262; White, 1954, pp. 410-415). In the early Miocene, two 
species of Leidymys and Paciculus insolitus are known from 
the middle John Day (Wood, 1936a). Eumys eliensis, from 
the equivalent Fort Logan of Montana (Black, 1961c, pp. 7-10), 
seems to be more closely related to E. hrachyodus of the plains 
than to the large Montanan species of Eumys described by White 
(1954). It seems possible that Cotimus (Black, 1961a) may be 



42 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

related to Paciculus, known only from the upper teeth (Wood, 
1936a, pp. 4-6; Black, 1961c, pp. 10-12). Scottinms kellamorum 
is a continuation of the Oligocene Scottimus lineage (Black, 
1961b). 

The only described North American cricetids between the early 
Miocene and the late Pliocene are : Horatiomys montanus (Wood, 
1935b, if it is a cricetid), and Pociculus montanus (Black, 1961c) 
from the Deep River of Montana ; Cotimus alicae from the Flint 
Creek of Montana (Black, 1961a) ; Miochomys niohrariensis from 
the Niobrara River (Hoffmeister, 1959) ; and four species of 
Copemys — C. longidens (Hall) from the late Miocene Barstow 
of California, G. kdloggae (Hoffmeister) from the late Miocene 
Niobrara River of Nebraska, C. loxodon (Cope) from the late 
Miocene or early Pliocene Santa Fe of New Mexico, and C. 
dentalis (Hall) from the early Pliocene Fish Lake Valle.v. An- 
other species of Copemys from the Fish Lake Valley is described 
below. 

The published record would indicate that the cricetids were 
nearly absent from the Great Plains area during the Miocene and 
most of the Pliocene, although they survived and evolved in the 
intermontane areas farther west. Even at such a semi-inter- 
montane area as Split Rock there are no cricetids among the 
thousands of rodent teeth known. The dominant North American 
Miocene small rodents were the entoptychine geomyids. In the 
Pliocene, their place seems to have been taken by the heteromyids. 
The cricetids do not come back into the picture until the end of 
the Pliocene, when both hesperomyine and microtine forms be- 
come abundant. Perhaps the invasion of the Old World micro- 
tines reduced the competing heteromyids, and allowed the native 
American cricetids to spread eastward once more. The presence 
of C. kelloggae in Nebraska and of cricetids in the Miocene of 
Florida (Wood, 1947, p. 491), however, shows that they were not 
completely absent in the great plains and farther east. 

The present evidence suggests that the hesperomyines were 
derived from the eumyines in a manner somewhat similar to that 
shown in Figure 5, and that the series Eumys — Leidymys — 
Copemys — Peromyscus is not far from a true phyletic sequence. 
The citation of Leidymys in the Oligocene is based on the refer- 
ence to that genus of L. vetus (Wood, 1937, p. 257). Galbreath 
(1953, p. 72) states that in his opinion Eumys exiguus and 
Leidymys vetus represent the same species. In this allocation 
he is followed by Black (1961b, p. 3). However, Leidymys is 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OV NEVADA 



43 



characterized by a well-developed hypocone-like cusp on M-^. In 
Eumys, includin<>' E. exiguus, this cusp is at most an enlarged 
cingulnm. Since Leidymijs is presumably derived from Eumys, 
the transition must have occurred as individual variants. But 
Eumys exiguus also shows the development of anteroposterior 
connections between the crests, leading toward Scottimus (Black, 
19611), p. 3, transfers it to Scottimus, which is just as reasonable 
as leaving it in Eumys), and there is no trace of these in the type 
of Leidymys vetus. The status of tlie Oligocene eumyine rodents 



UPPER 
PLIOCENE 
AND 
LATER 



ONYCHOMYS 



PEROMYSCUS 



EARLY 
PLIOCENE 



'C.ESMER- C.DENTALIS\ 



/ ALDENSISx 



LATE 
MIOCENE 



COTIMUS 
\ 
\ 
\ 
\ 



^. C.KELLOGGAE \, 



C.LOX- 
ODON 



MIOCHO- 
MYS 



C.LONGIDENS 



V 



"I 
COPEMYS 



MIDDLE 
MIOCENE 



PACICULUS 



\ 



\ 



EARLY 
MIOCENE 



PACICULUS 
\ 
\ 
SCOTTIMUS \ EUMYS 



\ 



LEIDYMYS 



\ 



\ ELIENSIS 
^^ ^ 



LATE 
OLIGOCENE 



\ / 

E.BRACHY- 

ODUS 



MIDDLE 
OLIGOCENE 



SCOTTIMUS /E.BRACHY- 



EARLY 
OLIGOCENE 



/ 



ODUS 



E. EXIGUUS 



\ 



LEIDYMYS 
VETUS 

LL_EUMYS 
/ COMPLEX 



/ 



E.ELE6ANS. 



Fig. 5. Phylogenctic iL']:itioiishij>s of North Aiiieric-an Tertiary crii-etids. 



44 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

will have to remain nebulous until the very extensive collections 
are studied, so that it will become possible to separate individual 
variations from specific and generic variants. There is so much 
variation among North American Oligocene cricetids that all 
possible later trends seem to be represented within a single 
population, sometimes even in the material from a single ant 
hill. Very few if any of the described forms can be considered to 
be adequately categorized and separated from each other. 

Cotimus (Black, 1961a, p. 73) is distinct from Copemys. It 
may represent the hitherto undescribed lower teeth of Paciculus. 
At any rate, as stated above, it is close to that genus, and not in 
the line leading to Peromyscus. 

Hoffmeister (1959, p. 698) has pointed out the similarities of 
Miochomys to Onyckomys (Fig. 5). The former genus is most 
probably also derivable from Leidymys. Horatiomys is as isolated 
as when it was first described (Wood, 1935b, p. 3). 

Copemys includes several forms at rather diverse levels of 
development. All the species seem to be evolving in slightly dif- 
ferent directions, and the data are not adequate at present to 
determine ancestor-descendant relationships among the group. 
The alternation of the buccal and lingual cusps and the shifts 
in the points of attachment of the various cusps and crests are 
progressive features foreshadowing Peromyscus. 

Copemys loxodon (Cope) 
Figures 6-7 

II esperomys loxodon Cope, 1874, jj. 148. 
Eitmys loxodon (Cope). Cope, 1875, p. 993. 
Peromyscus loxodon (Cope). Hay, 1902, p. 727. 
Copemys loxodon (Cope). Wood, 1936a, p. 5. 

The synonymy given here, rather than that cited previously 
by Wood (1936a, pp. 5-6), is the correct one. 

Type: U.S.N.M. No. 1204, right lower jaw with Ii and Mj.o ; 
an isolated right I^ may belong to the same form, and an isolated 
right I] certainly does not. 

Hypodigm: Type only. 

Emended diagnosis: Well developed lingual mesolophids, ex- 
tending from posterior arm of protoconid to lingual margin of 
crown and ending in a distinct mesostylid ; posterior cingulum of 
M2 connecting with buccal rather than lingual margin of liypo- 
conid; masseteric fossa with everted, overhanging dorsal margin; 
tooth measurements as given in Table 4. 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 



45 




X 



o 






46 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



Descri'ptio7i: The masseteric fossa is quite unusual, in its over- 
hanging dorsal margin (Fig. 6). No suggestion of such a struc- 
ture is seen in other species referred to this genus, but there is 
clearly considerable interspecific variability in this respect (Figs. 
8E, 9F). The ventral margin of the fossa extends to the ventral 
border of the angular process, as in C. dentalis. The masseteric 
knob, at the front of the fossa, lies beneath the middle of Mj, 
and is more distinct than in C. dentalis, but less so than in C. 
esmeraldensis. The mental foramen lies just in front of the an- 
terior root of Mj as in the other species. There is a pronounced 
groove between M3 and the coronoid process. The latter passes 
the alveolar border by the middle of M3. 





Fig. 7. Copcmys loxodon, U.S.N.M. No. 1204, X 10. A, EM1-2; B, medial 
view of right lower incisor ; C, ventral view of right upper incisor ; D, dorsal 
view of another right lower incisor with same number. 



The cheek teeth of the only known specimen of this species are 
quite distinctive (Fig. 7A), and are farther removed from the 
Peromyscus pattern than are those of the other members of the 
genus. As suggested by Wood (1936a, p. 6), the closest relatives 
of this species seem to be "certain species from the Miocene and 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 47 

Plioceiu' of California and Nevada, which have been described 
as Peroniyscus," and which are liere referred to Copemys. The 
peculiar position of the posterior cinj^ulum of M2 is just as 
unique as it seemed in 1936 {op. cit., p. 6), but Hooper's recent 
study (1957) of tooth variation in Peromyscus shows how much 
variability can exist within a single living genus, and warns us 
to be careful about drawing the lines of specific or generic varia- 
tion too tightly among fossil forms. (The magnification shown 
for these teeth in Wood, 1936a, fig. 5, is incorrect, that figure 
being 7.5, rather than 5, times natural size.) 

The lower incisor (Figs. 6, 7B) is similar to that of other 
species of the genus. The anterior face is fairly flat. At the tip 
of the median side, there is an extensive flat area, where there 
has been interdental wear with the tooth of the opposite side. 
This is also present on the type of C. dentalis, but all other 
specimens are too broken to be sure whether this is a generic 
character, although it probably is. It w'ould probably be associ- 
ated with a well-developed Transversus mandibulae muscle. 

The upper incisor associated with this specimen (Fig. 7C) is of 
the correct size and general shape to belong here, but it cannot 
with certainty be referred to this form. Another lower incisor 
(Fig. 7D) is much too small for Copemys, and is too narrow and 
with too heavy an anterior enamel face to belong to a cricetid. 
It agrees in size, shape, and shape of the pulp cavity with the 
incisor of small heteromyids, and presumably is referable to a 
member of that family. 

Copemys dentalis (Hall) 
Figure 8 

Peromyscus dentalis Hall, 1930c, p. 306. 

Type: U. Cal. No. 29635, a lower jaw with lili and Mi_2. 

Hypodigm: Type, and U. Cal. No. 29636, edentulous right jaw, 
and U. Cal. No. 29638, left jaw with M1.2. 

Emended diagnosis: Fossa between M3 and the coronoid proc- 
ess bears small nutritive foramina; mental foramen below dia- 
stema as in C. loxodon; anteroconid area of Mi simple as in C. 
longidens, but larger than in C. loxodon; mesolophid present or 
absent, and low when present ; no distinct hypoconulid on Mi ; 
metaconid of M2-3 far forward, eliminating lingual half of 
anterior cingulum as in C. loxodon; low^er incisor narrow ; tooth 
measurements as given in Table 4. 



48 



BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 



Description: The tooth pattern of this species (Pig. 8 A-B) is 
more Peromyscus-\ike than is that of the genotype. The teeth 
show the Peromyscus type of alternation of cusps, but the cusps 
are still less completely integrated with the lophs than in Per- 
omyscus, warranting the reference of this species to a genus 
ancestral to Peromyscus, for which Copemys is the best name 
until a great deal more is known about Miocene and early Plio- 
cene North American cricetids. 







Fig. 8. Copemys dentalis. Teeth X 10, jaw X 5. A, U. Cal. No. 29635, 
RMi-2, type; B, U. Cal. No. 29638, LMi-o; C, U. Cal. No. 29635, type, cross 
section of right I:, from rear; D, TJ. Cal. No. 29636, cross section of right 
I], from front; E, lateral view of lower jaw, anterior lialf based on U. Cal. 
No. 29635, type, and rear half on U. Cal. No. 29636. 



In Mj , the anteroconid is somewhat larger than in C. loxoclon, 
and is close to the metaconid. There are distinct ridges running 
posteriorly from the protoconid, along the buccal margin of the 
tooth, in all teeth. These are also present on Mj of C. loxoclon 
(Fig. 7 A), but are less well developed in other species. The 
mesolophid (or posterior arm of the protoconid) is absent in all 
teeth except Mi of IT. Cal. No. 29638, where it extends as a faint, 
low ridge to the buccal margin of the tooth (Pig. SB). The 
hypoconulid seems poorly developed on M^, but distinct on M2. 

The incisor has a rounded anterior face with a heavy coat of 
enamel. It is slightly concave on the medial side of the type (Pig. 
8 C) which is not shown in the other specimen (Pig. 8 D), and 
is probably due to crushing, and, at this level, is certainly not due 
to interdental wear. 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 49 

Tlie jaw is slender, with no su>i'gest ion of a cliin pi'oeess. The 
mental foramen is below the posterior portion of the diastema. 
The masseteric fossa is shallower than in other species of the 
genus, being bounded by faint ridges, especially on tlie dorsal 
side (Fig. 8 E). The anterior end of the fossa is beneath the 
middle of Mj. Posteriorly, the ventral border of the fossa ap- 
proaches the ventral margin of the angle. The base of the 
incisor, in U. Cal. No. 2!)().'}(), I'oi-ms a knob on the lateral surface 
of the mandible, at the level of the molar alveoli but well behind 
them. This knob Is brok'cn through on the specimen. 

COPEMYS LONGIDENS (Hall) 

Peromyscus longidens Hall, 19.'501), i). .'515. 
Peromyscus sp. Hall, 19301), p. 310. 
Peromyscus sp. Hall, 1930b, p. 31(). 

All of Hall's specimens seem to be within the limits of one 
variable species, in which variation is no greater than in living 
species of Peromyscus (Hooper, 1957). 

There is a single anteroconid on M^ of the type, as in the 
previously discussed species. A crest, probably the mesolophid, 
reaches the lingual margin of the crown in the type. It is much 
smaller in U. Cal. No. 28503. In U. Cal. No. 28506, the cre.st is 
complete but its lingual half is very low. The isolated tooth of 
Hall's first Peromyscus sp. (U. Cal. No. 28517 ; it is Mj, not P4 as 
Hall stated) is about ten per cent smaller than the type specimen, 
and is somewhat (but not significantly) narrower than the other 
material. The isolated M2 of U. Cal. Xo. 28516 is intermediate 
in size between what would be expected for that of U. Cal. No. 
28517 and the rest of the population. 

There is a faint trace of an anterolingual cingulum on M^ of 
the type, but it is almost eliminated. The mesolophid is very 
short on tiiis tooth. 

The lingual anterior cingulum of M^ is very small. In the 
type, the entoconid and mesolophid are minute. There is a lingual 
marginal ridge connecting the metaconid and entoconid. 

The upper teeth show progressive development of lophs. In 
Ml of U. Cal. No. 28515 the metaconid unites with the middle of 
the posterior cingulum. In M-, there is the beginning of this 
posterior union (not shown in Hall's figure, 1930b, fig. 7 A), but 
the union between the metacone and hypocone is still i)resent. 
The mesoloph (or anterior arm of the hypocone) is well de- 
veloped. The tootli figured by Hall as M-' (op. cit., fig. 6) is 



50 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

actually a specimen of M^ in which both unions of the metacone 
are present, and the mesoloph is very long. 

The range of variation in tooth size is indicated in Table 4. 

The mental foramen lies beneath the diastema, as in C. dentalis, 
and the size and shape of the masseteric fossa is also like that of 
C. dentalis. 

CoPEMYS KELLOGGAE (Hoffmeister) 

Peromyscus Tcelloggae Hoffmeister, 1959, p. 698. 

This species, from the late Miocene Niobrara River fauna of 
Nebraska is referable to Copemys. The anteroloph is a single 
cusp, close to the metaeonid (Hoffmeister, 1959, fig. 1 B). There 
is a long mesolophid, reaching nearly to the lingual margin of 
the crown. The hypoconulid is very well developed. 

The upper molar described by Hoffmeister as Miochomys 
niohrariensis does not appear to be referable to the same form 
as do the lower teeth, although they are of the appropriate size 
to belong together. The metacone has not shifted its union away 
from the hypocone, and the posterior cingulum is short. The 
separation of the tooth into three transverse lobes is not char- 
acteristic of Copemys. 

Copemys esmeraldensis n. sp. 
Figure 9 

Type: M.C.Z. No. 7644, right jaw with Mi and M3 and incisor. 

Hypodigm: Type; M.C.Z. No. 7645, right jaw fragment with 
Mi; M.C.Z. No. 7646, edentulous right jaw; and M.C.Z. No. 
7647, left maxillary fragment with M^. 

Diagnosis: Jaw heavier than in C. dentalis. with chin process; 
masseteric fossa not reaching as far ventrad on angle as in C. 
dentalis and upper border of masseteric fossa more pronounced, 
but mucli less so than in C. loxodon; mental foramen beneath Mi 
rather than in front of it ; fossa between M3 and coronoid as in 
C. dentalis; anteroconid area highly complex ; mesolophid present 
and long, though sometimes low ; sometimes an accessory crest 
running buccad from the entoconid to the buccal margin of 
the tooth; hypoconulid of Mi distinct; metacone of M^ uniting 
with posterior cingulum rather than with hypocone ; lower 
incisor wide; larger than C. dentalis; tooth measurements as 
given in Table 4. 



51 






•2 ti d 






^1 






y. 



a'- 



-- t~ CO 00 









^IM 

H 






55 






So 

i5 



0-5> 



O CR rH 



•2 rii 



a 
o 

Is 






o 5 £? 

o _« ^- 



^ & 



& ii 



S ^ 






IS S - 3 '^ 



:3 5^ 5: 



rt ^ ^ 



52 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Distrihution : Lower Pliocene Fish Lake Valley beds, Esmer- 
alda Formation of Nevada. All material came from locality A 
shown by Hall (1930c, pi. 37, fig. 1). 

Description: As shown by the two specimens of Mi preserved 
in the present collection (Fig. 9 B, C) there is considerable 
variability in pattern in this tooth. From what is known of the 
variability in the Oligocene Eumys, and from the detailed studies 
of Peromyscus by Hooper (1957), however, it seems obvious that 
a great deal of individual variation can be expected within a 
single species of cricetid. Initially, because the specimens come 
from a single locality, all the Fish Lake Valley ericetids were 
referred to a single species. As the study proceeded, however, 
it became apparent that not only is the material in the present 
collection all much larger than Hall's material, but there is also 
the much greater complexity of the anteroconid region and the 
rather striking difference in the jaw structure, including the 
masseteric fossa and the position of the mental foramen. These 
differences make it seem unlikely that this material is conspecific 
with C. clentalis, even though the present collection came from 
the same spot as the University of California material. 

The pattern of M^ (Fig. 9 A) is fundamentally intermediate 
between that of Euynys clegans (AVood, 1937, fig. 57) and that 
of such living species of Peromyscus as P. nuclipes (Hooper, 
1957, fig. 19). The anterocone is a large cusp, continued both 
buccally and lingually by narrow ridges. Buccally, there are 
two such ridges, separated by a groove, as in P. nudipcs. The 
anterior arm of the protocone unites with the middle of the 
anterocone. The posterior arm of the protocone unites with the 
paracone to form a protoloph as in Eumys. In general, in 
Peromyscus, the paracone is behind the protocone, though this 
is not always the situation. This shift is just beginning in 
the present form. The mure is longer than in Peromyscus. The 
mesoloph, as in Eumys, is a continuation of the anterior arm 
of the hypocone, instead of appearing more closely related to 
the paracone, as in Peromyscus (Hooper, 1957, figs. 9, 15, 16 and 
19). The mesoloph is directed into the base of the metacone, 
rather than extending freely to or toward the buccal margin of 
the tooth as in Paciculus (Black, 1961c, fig. 4) or some species of 
Pero7nyscus (Hooper, 1957, figs. 18-19). The most progressive 
character of this tooth is the union of the metacone with the 
posteroloph, rather than with the hypocone. In this it resembles 
C. dentalis and is more advanced than 3Iiochomys niobraricnsis. 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OP NEVADA 53 

Even thounfh this union is characteristic of Peromyscus, not all 
members of that genus are as advanced as is Copemys dcntaUs. 
The measurements of this specimen are : anteroposterior, 2.27 
mm; width protoloph, 1.48; width metaloph, 1.52. 

The two sioeeimens of M^ are ratlier different, as well as being 
in very distinct stages of wear. Tlie unworn tootli (Fig. 9 C) 
shows tliat the anterolophid is a very eomph\\ area, being formed 
of an anteroeoiiid (partly divided in two), a large lingual eu.sp, 
a buccal marginal crest from the anteroconid, and a long, narrow 
crest from the lingual cusp almost to the buccal margin. The 
worn sjiecimen (M.C.Z. No. 7644, Fig. i) B) cannot be shown to 
have had a different pattern. This area is much more complex 
than anything seen in any other species of Copemys, or in Eumys, 
though the beginnings of subdivision of the anteroconid may be 
seen in E. ohliquidens (Wood, 1937, fig. 62) and E. spo'kancnsis 
(White, 1954, fig. 47). This area is much more complicated 
than is the corresponding area of any of the Peromyscus teeth 
figured by Hooper, though it is approached in P. nndipes 
(Hooper, 1957, fig. 19). The protoconid and metaconid unite 
at the anterior end of the metaconid, the latter cusp being the 
more anterior. This condition is typical of both Copemys and 
Peromyscus, and is a contrast to Eumys, where the primary 
union is at the posterior side of the protoconid. In C. loxodon, 
the metaconid is more isolated than in C. esmeraldensis. The 
ectolophid (in the sense of Wood and Wilson, 1936; this ridge 
is called the mure by Hooper, 1957, fig. 1) is much longer than 
in Eumys, being like that of Peromyscus in this respect. What 
may be a mesolophid extends from the middle of the ectolophid 
almost to the lingual margin of the crown, not being as elevated 
as is the ectolophid (Fig. 9 C). In M.C.Z. No. 7644 (Fig. 9 B), 
the mesolophid looks as if it were perhaps more correctly 
identified as the posterior arm of the protoconid, as in some 
specimens of Eumys (AVood, 1937, fig. 58). There is a connection 
in this same specimen between this lingual crest and the anterior 
side of the entoconid (Fig. 9 B). The entoconid connects with 
the ectolophid in front of the hypoconid, rather than with the 
anterior arm of the hypoconid as in Oligocene species of Eumys, 
resembling Eumys eUensis (Black, 1961c, fig. 3 A) and Pero- 
myscus in this respect. There is much more of a hypoconulid than 
in Eumys. An unusual crest that extends buccally from the 
point where the entoconid meets the ectolophid in one specimen 
(Fig. 9 C), is completely absent in the other (Fig. 9 B). This 



54 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



crest is present in many of the species of Peromyscus discussed 
by Hooper, the closest similarity being seen in P. nuttalli (Hooper, 
1957, fig. 18). This crest, which seems to be fairly important 
in Peromyscus, has been called the ectolophid by Hooper. It is 
completely unrelated to the ectolophid as that term was used 
by Wood and Wilson (1936) and does not seem to have been 
discussed by anyone else. This crest is clearly a neomorph in 
Copemys and Peromyscus, and does not arise as a buccal ex- 
tension of the mesoconid, which Wood and Wilson would have 
considered to be a buccal part of the mesolophid. Both of these 
teeth belong to Hooper's pattern type g (1957, p. 11). Of the 
species he studied, pattern g occurs in less than ten per cent 
of all except P. maniculatus (20%), P. truei (20%), P. hylocetes 
(25%), P. oaxacensis (60%) and P. mcxicanus (50%). A well 
developed buccal crest (Hooper's ectolophid) is present in all 
P. hylocetes and P. oaxacensis ; 90 per cent of P. yucatane7isis ; 
80 per cent of P. nasutus and P. difficilis; 70 per cent of P. 
hoylei; 30 per cent of P. leucopus and P. mexicayius ; 20 per cent 
of P. melanotis and less than ten per cent of the remainder. 








Fig. 9. Copemys esmeraldensis n. sp. Teeth X 10, jaw X 5. A, LM^, 
M.C.Z. No. 7647; B, type, EMi and M3, spaced as in the specimen, M.C.Z. 
No. 7644; C, EMi, M.C.Z. No. 7645; D, cross section of RIi, M.C.Z. No. 
7644, type; E, cross section of RIi, M.C.Z. No. 7646; F, lateral view of 
lower jaw, M.C.Z. No. 7644, type. Outline portion restored from M.C.Z. 
No. 7646. The incisor slid back into the alveolus before fossilization. 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OP NEVADA o5 

Therefore, as far as the avaihihh' data go, C. esmeraldensis seems 
closest to P. oaxacensis, aiiioii«;- the species studied by Hooper, 
ill these respects. 

The single specimen of M3 (M.C.Z. No. 7644, Fig. 9 B) is 
both badly worn and broken. Hooper does not discuss this 
tooth in Peromyscus. This tooth is very different from that of 
Enmys. There is no anterior cingulum, and the metacoiiid is 
continuous along the anterior edge of the tooth to the protoconid. 
From here, a broad ridge runs to the lingual margin of the tooth, 
showing slight irregularities at the tooth margin, which suggests 
that it may include a mesolopiiid and an entoconid, the latter 
being well forward of the hypoconid. A broad postcrolophid 
extends across the rear of the tooth. 

The incisor is broad, with a rounded anterior face, and is 
proportionately wider and rounder, laterally, than in C. dentalis. 
The enamel is fairly thick, and extends well onto the lateral side 
of the tooth (Fig. 9 D-E). The pulp cavity enlarges toward the 
enamel-covered side of the tooth (Fig. 9 E). The base of the 
incisor is in the ascending ramus behind and at or above the level 
of M3 (Fig. 9 F). 

Three lower jaws are preserved permitting the composite restor- 
ation shown in Figure 9 F. There is a prominent chin process 
in M.C.Z. No. 7646, not preserved on the other specimens. Such 
a process does not seem to have been present in C. dentalis (Hall, 
1930c, fig. 16). This difference may be sexual, but the overall 
differences in size and in tooth pattern suggest that it is not. 
The symphysis is weakly ridged, indicating that there may have 
been a strong Transver.sus mandibulae muscle and free movement 
between the mandibles. The alveolar border drops abruptly in 
front of Ml, as in C. loxodo7i, in contrast to its more gentle slope 
in C. dentalis and C. longidens. The prominent mental foramen 
lies beneath the anterior root of Mi, as in C. loxodon, instead of 
beneath the diastema as in the other species, and opens anterad 
rather than slightly upward. The masseteric fossa is broad and 
flat. The masseteric knob is clearly differentiated, beneath the 
posterior end of Mi, farther to the rear than in C. dentalis (Hall, 
1930c, figs. 16-17). The masseteric fossa does not extend as far 
ventrally in the angle as in C. dentalis. The coronoid process 
passes the alveolar border by the middle of Mo. There is a prom- 
inent fossa between M.-j and the base of the coronoid, which con- 
tains one or more nutritive foramina, as in othei- species of the 
genus. 



56 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

At the present time, little can be said of the interrelationships 
of the five species of Copcmys. C. esmeraldensis is probably the 
closest to Peromyscus. C. loxodon is apparently the most aber- 
rant. C. longidens may be ancestral to C. esmeraldensis. The 
differences between C. longidens and C. dentalis are not great 
except in size, which may not be very significant, phylogenetic- 
ally. Copemys kelloggae is fairly close to C. longidens and C. 
dentalis. These three species are all closer to each other than any 
is to C. esmeraldensis or C. loxodon. 

Family CASTORIDAE 

EucASTOR DiviDERUs Stirton, 1935 

Figure 10 

Aside from lagomorph material, fragmentary remains of this 
beaver are the most abundant fossils in the collection. The pres- 
ent material adds some features to the full account of this species 
given by Stirton (1935, pp. 431-437). Two upper premolars, 
M.C.Z. Nos. 7648 and 7649, show interesting pattern variants, and 
M.C.Z. No. 7650 is an upper deciduous premolar, hitherto not 
described. 

In both of the permanent premolars, the anteroloph is very 
long, covering the entire front of the tooth, as opposed to the 
earliest stage of wear figured by Stirton (1935, fig. 107). The 
parastria is present in one specimen (Fig. 10 A), but is con- 
verted to a parafossette in the other (Fig. 10 B). In each speci- 
men, there is a small enamel lake, of very uncertain homology, in 
the middle of the paracone. The mesoflexus in the less worn 
specimen extends across the tooth to the posterior margin of the 
crown, where it forms a distinct flexus behind the hypocone 
(Fig. 10 A). In the more worn specimen, this is cut off from 
the posterior margin of the crown, as in Stirton 's specimens. 
There is considerable variation in the region of the metaflexus. 
In Stirton 's least worn tooth (1935, fig. 107), the metaflexus 
opens to the rear, and there is a small isolated lake behind it. 
In M.C.Z. No. 7648, the metaflexus is a triangular valley, opening 
posteriorly (Fig. 10 A). In the more worn premolar, the meta- 
fossette is widely separated from the rear of the tootli, resembling 
Stirton 's second stage of wear {op. cit., fig. 107), but retaining 
a minute lake behind the fossette. 

Presumably these variants indicate that there are numerous 
minor irregularities at the surface of the unworn crown, and 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OP NEVADA 



57 



that tliese ai-e liio-lily variable, ^iviii^' a variety of slightly dif- 
ferent patterns with wear. The exact angle at which the wear 
surface cuts the crown may also make appreciable pattern dif- 
ferences. 

The upper milk tooth (Fig. 10 C) is clearly deciduous, as it 
is much lower crowned than are the permanent teeth. There 
was a large single root under the anterior part of the crown, and 
two smaller ones under the posterior part. The anterior root, 
however, is proportionately smaller than in P^. The hypostria 
and mesostria extend almost to the base of the crown. The 
metastria is long, but not (juite as long as the other two. The 
mesoflexus and metaflexus interconnect, isolating a circular buc- 
cal mesostyle. The metaflexus runs transversely across the pos- 
terior part of the tooth, and is much more extensive than in 
P-*. The paraflexus is already transformed into a parafossette. 




Fig. 10. Eitcastor dividcrus, X 5. A, EP^, M.C.Z. Xo. 7648; B, RP-», 
:\r.C.Z. Xo. 7G49; C, EdP^, M.C.Z. Xo. 7650. 



Family IIETEROMYIDAE 

DiPRioNOMYS cf. PARVUS Kellogg, IJilO 

Two isolated and unassociated unworn cheek teeth are perhaps 
referable to this species: M.C.Z. No. 8535, RP^ and M.C.Z. No. 
8536, RM2. Since the previously known material is badly worn, 
they add considerably to our knowledge of this rodent. 

The premolar (Fig. 11 A) is clearly that of a heteromyine, 
in view of the two-cusped protoloph. The buccal cusp is quite 
small, and distinctly subsidiary to the main cusp. The metaloph 
forms a crest of nearly uniform height, running fi-oni the meta- 
eone to the hypostyle, and passing behind the slightly higher 
hypocone. The hypostyle is at about a right angle with the rest 
of the metaloph. The valley between the hypostyle and the 
hypocone curves buccad behind the latter, but would not persist 
verv long with wear. 



58 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

The molar (Fig. 11 B) is eonsiderd to be M2 rather than M^ 
because of its anteroposterior diameter, which is less than would 
be expected in Mj (cf. Wood, 1935a, Table II). Both lophs 
are strong, and the cusps form only minor enlargements. The pro- 
toconid is the only really distinct cusp. There is a prominent 
valley between the protoconid and protostylid, which would re- 
sult in the formation of a Y-pattern, a characteristic heteromyine 
feature (Wood, 1935a, p. 165). The hypolophid is almost a 
straight crest, the cusps being very indistinct. The least depth 
of the central valley is between the two stylids, and the valley 
would thus become closed, buccally, after a moderate amount 
of wear. Slight further wear would unite the lophs just linguad 
of the bases of the protoconid and the hypoconid, isolating the 
buccal part of the valley as a lake. This double union is char- 
acteristic of Diprionoynys (Wood, 1936b, p. 118). 




Fig. 11. Diprionomys cf. parvus, X 10. A, EP-^, M.C.Z. No. 8535; B, 
RM2. M.C.Z. Xo. 8536. 



These specimens are the first from the Fish Lake Valley beds 
that can be referred to Diprionomys, Hall's two species (D. 
tertius and D. quartus) being perognathines which AVood (1935a, 
pp. 92-96) placed in a separate genus, Pcrognathoides. The two 
teeth here described are, however, clearly heteromyines, and seem 
clearly to be referable to Diprionomys. They are the right size 
to belong onh' to D. parvus among descril)ed species, and cannot 
at the present time be separated from that species, even though 
the type is appreciably later (Thousand Creek). 

The measurements of these specimens are as follows : 



M.C.Z. No. 8535, Rp-i 
M.C.Z. No. 8536, RMo 



A small collection of Pliocene mammals, from the type locality 
of the Fish Lake Valley local fauna of Nevada, adds ap])i'ecial)l.v 
to our knowledge of that fauna. Included ai'e : a talpid, Doiiniin- 
oides; Hesperolagomys, a new genus of ochotonid ; a new species, 
C. esmeraldcnsis, of the cricetid Copcmys; and the heteromyid 



antfi-d- 
l)osterii)i' 


width 
anterior 

orest 


wiilth, 

ixistcrior crest 


1.40 


0.77 


1.43 


1.02 


1.27 


1.23 


SUMMARY 







CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF NEVADA 59 

Diprionomys. The most abundant material, referable to the 
rabbit JhjpoJaijus f()nti)i(ilis, and the l)eaver Eucasfor dividerus, 
adds to our kno\vU'd<«(' of the dentition of these forms. 

These materials permit a discussion of the interrelationships 
and evolutionary trends amon^ Tertiary North American ocho- 
tonids and cricetids. Hespcrolagornys is an unusually primitive 
Pliocene ochotonid, ajiparently representing: the survival of a 
line derived from the primitive stock of the family, ])erha})s from 
Desmatolagiis. The cricetid genus Copemys is revised, and three 
species previously included in Pcro)nyscus are referred to it. Al- 
though cricetids are abundant in the middle Oligocene, the North 
American Miocene and Pliocene cricetids are largely limited to 
intermontane areas, with only two isolated teeth from the late 
Miocene Niobrara River local fauna of Nebraska and rare speci- 
mens from the Thomas Farm local fauna of Florida. They do 
not appear in numbers in the plains until the late Pliocene. 
Competition with entoptychine geomyids and with heteromyids 
may be the factors involved in the reduced numbers of cricetids 
in the Miocene and early Pliocene. 

EEFEEENCES 

Black, C. C. 

1961a. Fossil mammals from Montana. Pt. I. Additions to the T.ate 
Miocene Flint Creek Local Fauna. Ann. Carnegie Miis., 36: 
69-76. 
1961b. New rodents from the early Miocene deposits of Sixty-Six 
Mountain, Wyoming. Breviora, Mus. Comp. Zool., No. 146: 1-7. 
1961c. Kodents and lagomorphs from the Miocene Fort Logan and 
Deep Eiver formations of Montana. Postilla, Yale Peabody 
Mus., No. 48: 1-20. 
BOHLIN, B. 

1942. The fossil mammals from the Tertiary do])osit of Taben-buluk. 
Western Kansu. Pt. I. Inseetivora and Lagomorpha. Palaeont. 
Sinica, n.s. C, 8 a: 1-113. 
Burke, J. J. 

1941. New fossil Leporidae from Mongolia. Amer. Mus. Novitates, 
No. 1117: 1-23. 
Cope, E. D. 

1874. Notes on the Santa Fe marls and some of the contained verte- 
brate fossils. Proc. Acad. Nat. Sci. Phila., 26: 147-152. 

1875. Keport on the geology of that part of northwestern New Mexico 
examined during the field season of 1874, by E. D. Cope, palae- 
ontologist and geologist. Appendix LL, Ann. Eept. Chief of 
Engrs., Ann. Eept. Geogr. Ex]il. & Surv. West of 100th Merid- 
ian, Washington: 981-1036. 



60 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY 

Dawson, M. E. 

1958. Later Tertiary Leporidae of North America. Univ. Kansas 
Paleont. Contrib., Vertebrata, 6: 1-75. 

Forsyth Major, C. I. 

1899. On fossil and Recent Lasomorpha. Trans. Linn. Soc. London, 
(2), Zoology, 7: 433-520. 
Galbreath, E. C. 

1953. A contribution to the Tertiary geology and paleontology of 
northeastern Colorado. Univ. Kansas, Paleont. Contrib., Ver- 
tebrata, 4: 1-120. 
Green, M. 

1956. The lower Pliocene Ogallala-Wolf Creek vertebrate fauna, South 
Dakota. Jour. Paleont., 30: 146-169. 

Hall, E. R. 

1930a. A new genus of bat from the later Tertiary of Nevada. Univ. 

Calif. Publ., Bull. Dept. Geol. Sci., 19: 319-320. 
1930b. Rodents and lagomorphs from the Barstow beds of southern 
California. Univ. Calif. Publ., Bull. Dept. Geol. Sci., 19: 313-318. 
1930e. Rodents and lagomorphs from the later Tertiary of Pish Lake 
Valley, Nevada. Univ. Calif. Publ., Bull. Dept. Geol. Sci., 19: 
295-312. 
Hay, O. p. 

1902. Bibliography and catalogue of the fossil A'^ertebrata of North 
America. Bull. U.S. Geol. Surv., 179: 1-868. 

HOFPM BISTER, D. F. 

1959. New cricetid rodents from the Niobrara River fauna, Nebraska. 
Jour. Paleont., 33: 696-699. 

Hooper, E. T. 

1957. Dental patterns in mice of the genus Peromyscus. Misc. Publ. 
Mus. Zool., U. Mich., 99: 1-59. 

MacInnes, D. G. 

1953. The Miocene and Pleistocene Lagomorpha of East Africa. Brit- 
ish Mus. (Nat. Hist.), Fossil Mamm. Africa, 6: 1-30. 
McKbnna, M. C. 

1960. The Geolabidinae. A new subfamily of early Cenozoic erinace- 
oid insectivores. Univ. Calif. Pu1)l. Geol. Sci., 37: 131-164. 

Matthew, W. D. 

1909. The Carnivora and Insectivora of the Bridger Basin, middle 
Eocene. Mem. Amer. Mus. Nat. Hist., 9: 291-567. 
Patterson, B. and P. O. McGrew 

1937. A soricid and two erinaceids from the AVhite River Oligocene. 
Geol. Ser. Field Mus. Nat. Hist., 6: 245-272. 
Reed, K. M. 

1960. Insectivores of the middle Miocene Split Rock local fauna, Wy- 
oming. Breviora, Mus. Comp. Zool., No. 116: 1-11. 
Stirton, R. a. 

1935. A review of the Tertiary beavers. Univ. Calif. Pul)l., Bull. Dept. 
Geol. Sci., 23: 391-458. 



CLARK, DAWSON, WOOD : FOSSIL MAMMALS OF NEVADA 61 

White, T. E. 

195-1. Preliminary analysis of the fossil vertebrates of the Canyon 
Ferry reservoir site. Proc. U.S. Nat. Mus., 103 (3326) : 395-438. 
Wood, A. E. 

1935a. Evolution and relationships of the heteioinyid lodcnts with new 
forms from the Tertiary of western North America. Ann. Car- 
negie Mus., 24: 73-262. 

1935b. Two new genera of cricctid rodents from the Miocene of west- 
ern United States. Anier. Mus. Novitates, No. 789: 1-3. 

1936a. The crieetid rodents described by Leidy and Cope from the 
Tertiary of North America. Amer. Mus. No%'itates, No. 822: 1-8. 

19361). Fossil heteromyid rodents in the collections of the University 
of California. Amer. Jour. Sci., (5) 32: 112-119. 

1936c. Geomyid rodents from the middle Tertiary. Amer. Mus. Novi- 
tates, No. 886: 1-31. 

1937. The mammalian fauna of the White Eiver Oligoeene. Pt. II. 
Rodentia. Trans. Amer. Phil. Soc, n.s. 28: 155-269. 

1947. Miocene rodents from Florida. Bull. Mus. Comp. Zool., 99: 
489-494. 
Wood, A. E. and R. W^ Wilson 

1936. A suggested nomenclature for the cusps of the cheek teeth of 
rodents. Jour. Paleont., 10: 388-391. 
(Received December 1962) 

ADDENDUM 

Since this manuseiMpt was completed, three papers, two deal- 
ing with Barstovian and Clarendonian, and one with Arikareean, 
cricetids have appeared. Shotwell (1963, p. 49) refers a lower 
jaw from the Clarendonian of eastern Oregon to Peromy.^ctis 
cf. dentalis. James (1963, pp. 112-129) describes a considerable 
collection from the Clarendonian of the Cuyama area of Cali- 
fornia as Peromysciis russelli, and refers a single lower jaw from 
the Barstovian of the same area to Peromysciis aff. dentalis. 
Macdonald (1963, pp. 198-201) describes Eumys hlocli and 
E. wood}, and lists Scottimus, sp. indet., from the Arikareean 
of South Dakota. 

Shotwell 's specimen is a jaw containing the first lower molar 
of an animal very similar to the type of Copemys dentalis (Fig. 
8A). His figure (1963, fig. 52a) suggests an almost complete 
union of the anterolophid with the protoconid, which is incor- 
rect, as there is a broad but shallow valley in this area, similar 
to that shown in Figure 8A. The metaconid is close to the 
anteroconid, also as in C. dentalis, to which this specimen clearly 
should be referred. 



62 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

James' description of Pcromyscus russelli indicates that it 
is very close to its contemporary, Copemys csmcraldensis, and 
that the two are certainly cono'eneric. The Cnyama form shows a 
union of the paracone of M^ with both the anterior and posterior 
arms of the protocone, a condition more progressive than that 
seen in C. esmeraldensis. This type of union is present on M^^ 
as well (James, 1963, figs. 47, 52), and this species has thus 
progressed half way from the Eumys condition toward the 
situation in Peromyscus, where the union is exclusively through 
the anterior arm of the protocone. As in Copemys, the metacone 
of Ml has shifted its point of attachment from the hypocone to 
the posteroloph, whereas this shift has not occurred in 'M-'^. In 
the lower teeth, the pattern of M3 is almost identical in the 
two populations (compare Fig. 9B and James, 1963, fig. 53a). 
In M] , the California specimens show the same variation as to 
the presence or absence of the crest called the ectolophid by 
Hooper and by plames (but not that called the ectolophid by 
Wood and Wilson). The peculiar accessory crests and cusps of 
the anteroconid region of C. esmeraldensis (Fig. 9C) do not 
seem to be present in the California species. 

In spite of the similarity in pattern, there are significant 
distinctions in size, especially of the first molars. The length and 
width measurements of M^ of M.C.Z. No. 7647 exceed those of 
the mean of P. russelli (James, 1963, Table 22) by about six 
times the standard deviation, and the length of the smaller M^ 
of C. esmeraldensis exceeds that of P. russelli by over five times 
the standard deviation. The transverse diameter of M^ of the 
larger Nevada specimen is larger by nearly 3.5 S.D. The third 
molar of M.C.Z. No. 7644 is larger than that of any specimen of 
P. russelli, but the difference is not significant. The probability 
that either measurement of M^ or of Mj of C. esmeraldensis 
falls wdthin the limits of variation for the population of P. 
russelli is thus considerably less than .001, and is therefore 
negligible. 

These factors all indicate that Peromyscus russelli should be 
referred to Copemys, and that C. russelli and C. esmeraldensis 
are closely related but distinct species. 

The specimen referred by James to Peromyscus aff. dentalis 
is appreciably smaller than are the other specimens of C. den- 
talis, as James indicates (1963, p. 129), with an alveolar length 
of only 3.6 mm (cf. Table 4, where that of C. dentalis is given 
as 4.35-4.40 mm). It seems probable that this difference is great 



CLARK, DAWSON, WOOD: FOSSIL MAMMALS OF XEVADA 63 

enough to place James' specimen outside the limits of C. dentalis. 
It is presumably also referable to Copemys. 

PcroDiyscus parvus Sinclair (1905, p. 126) from the middle 
John Day of Oregon, was included by James as a rather dis- 
tinctive species of Peromyscus, only (luestionably ret'eraljle to 
the modern genus (1963, p. 128). Study of the only known 
specimen shows that it is clearly a small species of Lcidymys. 

In liis paper on Arikareean fossils from South Dakota, Mac- 
donald describes Eumys black i (1963, p. 198, fig. 21), which is 
clearly congeneric with Coiimus, and E. woodi {op. cit., p. 199, 
fig. 22), which is close to E. eliensis. He also refers two isolated 
upper molars to Scott inins sp. indet., thus extending the range 
of this genus into the Arikareean. 

ADDITIONAL KEFERENCES 

James, G. T. 

1963. Paleontology and nonniarine stratigraphy of the Cuyania Bad- 
lands, California. Part 1. Geology, faunal interpretations and 
systematic descriptions of Chiroptera, Insectivora and Eodentia. 
Univ. Calif. Publ. Geol. Sei., 45: 1-154. 
Macdonald, J. R. 

19G.3. The Miocene faunas from the Wounded Knee area of western 
South Dakota. Bull. Amer. Mus. Nat. Hist., 125: 1.39-238. 
Shotwell, J. A. 

1963. The Juntura Basin: studies in earth history and paleoecology. 
Trans. Amer. Phil. Soc, n.s. 53: 1-77. 
Sinclair, W. J. 

1905. New or imperfectly known rodents and unyuhites from the Jolui 
Day series. Univ. Calif. Publ., Bull. Dept. Geol., 4: 125-143. 



Bulletin of the Museum of Comparative Zoology 

H A H \ A j{ I) 11 N I \ !•; i{ s I r ^ 

Vol. 131, No. A 



AMERICAN SPIDERS OF TlIK GENUS PIIORONCIDJA 
(ARANEAE: TIIERIDIIDAE) 



By Herbert W. Levi 



CAMBEIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

April 30, 1964 



Publications Issued by or in Connection 

WITH THE 

MUSEUM OF COMPARATIVE ZOOLOGY 
PIAEVAPvI) UNIVERSITY 



Bulletin (octavo) 1863 — The current volume is Vol. 131 . 

Breviora (octavo) 1952 — No. 203 is current. 

Memoirs (quarto) 18G4-1938 — Publication terminated with Vol. 55. 

Johnsonia (quarto) 1941 — A publication of the Department of 
Mollusks. Vol. 4, no. 41 is current. 

Occasional Papers of the Department of Mollusks (octavo) 
1945 — Vol. 2, no. 28 is current. 

Proceedings of the New England Zoological Club (octavo) 
1899-1948 — Published in connection with the Museum. Publication 
terminated with Vol. 24. 

The continuing publications are issued at irregular intervals in num- 
bers which may be purchased separately. Prices and lists may be 
obtained from the Publications Office of the Museum of Comparative 
Zoology, Cambridge 38, Massachusetts. 



Peters' Check-List of Birds of the AVorld. Volumes 1, 4 and (> are 
out of print ; volumes 2, 3, 5, 7, 9, 10 and 15 are currently available. 

Phylogeny and Evolution of Crustacea. Proceedings of a confer- 
ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington 
and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. 
Cloth bound. $6.75. 

Fishes of the Gulf of Maine, by Henry B. Bigelow and William C. 
Schroeder. Washington, viii - 577 i)p., 1953. Photo-offset reprint. $6.50. 



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Bulletin of the Museum of Comparative Zoology 

H A 1{ V A J{ I) [• N I V K K S I T Y 

Vol. 131, No. 3 



ami^:hican spideks of the genus piioroncidia 
(araneae: tiieriditdae) 



By Herbert \V. Levi 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

April, 1964 



Bull. .Mus. Coiiip. Zool., Harvard Univ., 131 (3): 65-86, April, 1964 

No. 3 — American Spiders of the Genus Phoroncielia 
{Araneae: Theridiidae) 

By Herbert \V. Levi 



Phoroncielia are mostly small spiders with the abdomen hard 
and sclerotized but of various shapes. The diversity in shape 
has caused araelmologists to assign different species to separate 
genera. Thus the synonymy of generic names (Levi and Levi, 
1962) is long. Some species are similar to those placed in 
Dipoena (Hickman, 1951). However Dipoena females always 
have four seminal receptacles, while Fhoroncidia have two. In 
Dipoena, males, if the palpal embolus is long it curls counter- 
clockwise in the left palpus; in Phoroncidia, the direction is the 
reverse. It is believed that the similarities, heavy sclerotization 
of the abdomen (only some species of Dipoena), projecting eye 
region of the carapace, and the relatively long fourth leg, have 
independently evolved. Xothing is known of the natural history 
of Phnroyicidia species. 

The Central and South American P. fricuspidata, group, leav- 
ing three spines on the abdomen (Figs. 50, 56), is closest to its 
African relatives, some of which have five spines on the abdo- 
men : two anteriorly, as in the American species, and three pos- 
teriorly. The commonest species is the North American P. ameri- 
cana, closely allied in shape and appearance to the European 
P. paradoxa (Lucas), and the Japanese P. pilida (Karsch) ; 
most other species are very rare. Almost half the specimens 
available were collected during the nineteenth century and 
these old specimens, collected by entomologists, are often in poor 
condition, having been speared on insect pins. The scarcity of 
specimens, and the abundance of species, make it difficult to 
match sexes. The paper thus reports only our very incomplete 
knowledge of the American species. Despite this, I have resisted 
the temptation of quoting unsupported literature records. T 
have not been able to examine the Mello-Leitao collection to 
verify his many records of P. tricuspidata. I suspect many are 
misidentified. 

This paper, along with my others on American theridiid 
spiders, would not have been possible without the help of nu- 
merous colleagues who made rare specimens available. I extend 
sincerest thanks to Prof. j\I. Vachon of the Museum National d' 
Histoire Xaturelle, Paris (MNHN), Dr. A. Collart and Mr. J. 



68 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Kekeiibosch of the Institut Royal des Sciences Naturelles de 
Belgique (ISNB), Dr. L. Brundin of the Natural History Mu- 
seum Stockholm (RMS), Prof. G. C. Varley and Mr. E. Taylor 
of the Hope Department of Entomology, Oxford University, Dr. 
G. Owen Evans, Mr. K. Hyatt and IMr. D. Clark of the British 
Museum (Natural History) (BMNH) ; Dr. W. J. Gertsch of the 
American Museum of Natural History (AMNH), Dr. 0. Kraus 
of the Senckenberg Museum (SMF), and Mr. W. Starega of the 
Polish Academy of Sciences, Warsaw. Dr. P. E. Vanzolini and 
his colleagues of the Departamento de Zoologia, Sao Paulo, pro- 
vided locality information. Fr. Chrysanthus checked the latin- 
ization of specific names. The examination of types in European 
museums was made possible by a National Science Foundation 
Grant (G-4317), and the completion of the revision by a grant 
from the National Institutes of Health (AI-01944). 

Phoroncidia Westwood 

Phoroncidia Westwood, 183.5, Zool. Jour., 5: 452. Type species lay mono- 
typy: P. aculeata Westwood, 1835, ibid., 5: 453, tab. 22, fig. 9, 9,$ 
from ^lalaya. 

Note. It is not known whether Westwood 's specimens still 
exist. Only a few specimens determined by Berland in the Paris 
museum were examined. We recently published the synonymies 
(Levi and Levi, 1962). 

Diagnosis. Theridiid spiders with colulus replaced by two 
setae, usually hidden underneath a sclerotized ring surrounding 
spinnerets. Carapace with eye region projecting above clypeus. 
Small chelicerae. Legs very short; fourth leg usually longer 
than first. Abdomen of various shapes, heavily sclerotized, often 
leathery, folded or with strong spines, humps, tubercles or ex- 
tensions. 

Epigynum a heavily sclerotized plate with openings, often 
indistinct, in the center or on the posterior border. Juvenile 
specimens may also have the epigastric area sclerotized. Only 
examination for the presence of seminal receptacles will deter- 
mine whether the specimen is mature. The palpus usually has 
a paracymbial hook on or near the edge of the cymbium and the 
median apophysis probably does not touch the hook. 

Distribution. Species are found in all parts of the world ex- 
cept northern Europe and western North America. 

Misplaced species. Herihertvs fJavomacxlatns Keyserling, 
1891, Die Spinnen Amerikas, Theridiidae, 2(1) : 223. Ulesatiis 



LEVI: .\Mi:iil(AX I'lIOIJOXflDIA 6!) 

flavoiiuiciilata, — Petninkcvilcli. 1!)11, Uull. Aiiht. Mus. X;i1. 
Plist., 2!*: 214 ~ DipoiiKt flartjiiKicuhftd ( K('ys('rliii<i'j [not 
"Vmfila JlaronnicKhitd, — Potninkcvitcli," Levi. 11)63, Bull. 
Mus. Comp. Zool., 121* : 151, a misprint]. 

Tricaniha alhopuncfaia Taezanowski, 1879, Iloi-ao Soc. Ent. 
Rossicae, 15: 123, pi. 2, fi<>-. 36 = Arancus alhopinictahis (Tae- 
zajiowski), AK(UOrrDAE. 

KKY TO A.MKinCAX I'llOl.'OM 1 1 )I A 

1.1. AliiloiiH'u with spines, liunips, tubercles or pro.iectioiis 5 

11). Ahdoiuoii witliout spines, liumps, tubercles or projections 2 

2a. Dorsum of abdomen witli many trapezoidal plates (Fig. 11); 

Amazon studo 

2b. Dorsum of abdomen covered by one single plate 3 

3a. Trapezoidal imiiressions on dorsal jjlate (Fig. 17) ; Tjower Amazon 

lo)itiicrp.s 

31). Dorsal plate without trapezoidal impressions 4 

4a. Lateral eyes on tuljercles (Fig. 2) ; Peru nioiialxnuha 

4b. Lateral eyes not on tubercles (Fig. 23) ; Est. Rio de Janeiro 

riibroinaciihitd 

5a. Abdomen subcii-cular in outline in dorsal view (Fig. 20) 6 

5b. Abdomen tra])('zoidal, subtriangular or squarish with posterior i)ro- 

jections 7 

6a. Abdomen with only a median dorsal hump (Fig. 20); Chile snituJa 

6b. Abdomen with a median dorsal hump and paired humjis posteriorly 

(Levi, 1955, figs. 7, 8) ; eastern Canada, eastern L^nited States, Cuba, 

Jamaica americana 

7a. Abdomen widest anteriorly and with a median dorsal posterior s])ine 

(Figs. 29, 45, 56) 11 

7b. Abdomen as wide anteriorly as posteriorly, or wider ])osteriorly than 

anteriorly, usually without median posterior spine 8 

8a. Abdomen trapezoidal in dorsal view with five dorsal spines (Figs. 36, 

37) ; Minas Gerais Una 

8b. Abdomen otherwise 9 

9a. Abdomen with sides tuberculate and wrinkled (Figs. 32, 34) ; Chile 

margamarga 
9b. Abdomen with at most median dorsal tubercles; with sclerotized 

plates 10 

10a. Abdomen with longitudinal row of dorsal tubercles (Figs. 40, 41) ; 

Chile coquimbo 

10b. Abdomen with sclerotized spots but without tubercles (Figs. 25, 26) ; 

Chile nicoleti 

11a. Median posterior dorsal spine longer than anterior spines (Fig. 45) 

12 
lib. Three spines subequal in length 13 



70 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

12a. Innumerable dorsal circular plates of abdomen almost touching (Fig. 

29) ; Venezuela ravot 

12b. Fourteen dorsal circular plates, far apart (Fig. 45) ; Peru 

sciifellata 
13a. Epigynum with a distinct me(liaii opening (Fig. 78) ; Est. Sao Paulo 

to Est. Eio Grande do 8ul rcimoseri 

131). Epigynum otherwise 14 

14a. Epigynum with a V-shaped depression anterior to and between two 

dark spots containing openings (Fig. 73); Colomliia sahoya 

14b. Epigynum otherwise 15 

15a. Epigynum with paired openings near posterior margin (Fig. 58) ; 

Peru flavolim'bata 

15b. Epigynum otherwise 16 

16a. Openings of epigynum indistinct lateral slits (Fig. 47) ; Est. Guana- 

bara, Rio de Janeiro tricnspidata 

16b. Epigynum otherwise 17 

17a. Epigynum with a pair of distinct openings in a flat plate, anterior to 

a transverse keel (Fig. 63) ; southern Mexico, Central America 

triunfo 

17b. Epigynum otherwise 18 

ISa. Epigynum with a median depression containing openings 19 

18b. Epigynum without median depression, openings a pair of slits (Fig. 

68) ; Minas Gerais hiocellata 

19a. Spines relatively short (Fig. 56) ; distinct pair of openings in de- 
pression of epigynum (Fig. 53) ; Paraguay cribrata 
19b. Spines relatively long (Fig. 86) ; openings in epigynum depression 

indistinct (Fig. 83) ; Venezuela gira 

Phoroncidia moyobamba sp. n. 
Figures 1-5 

Wihrada longiceps, — Archer, 1950, Paper Alabama Mus. Nat. Hist., no. 
30: 27, pi. 4, fig. 4, $. Not IVibrada longioeps Keyserling. 

Type. Male holotype from Moyobamba, San Martin, Peru, 20 
Dec. 1946 (J. C. Pallister), in the American Museum of Natural 
History. The name is a noun in apposition after the type locality. 

Description. Carapace, sternum dark brown ; legs lighter 
brown. Abdomen, dorsum shiny brown ; venter brown with a 
Avhite spot on each side of pedicel, a Avhite mark behind epigas- 
tric groove, brown ring around spinnerets, and a small white 
mark on each side of ring around spinnerets. Sides and clypeus 
of carapace punctate, dorsum almost smooth. Median eyes on 
stalk; lateral eyes on tubercles (Fig. 2). Anterior median eyes 
larger than others, slightly less than a diameter apart. Poste- 
rior median eyes one and one-half diameters apart. Sternum 



LKVI : AMKRICAN 1' I lOIJOXClDlA 71 

punctate. Dorsum of abdomen heavily selerotized, domed, with 
paired slight depressions; venter folded with many sclerites 
(Figs. 3-5). Total length l.fi mm. Carapace 0.8 mm long, 0.6 
mm wide. First patelhi and tihia, 0.4 mm; second, 0.3 mm; 
third, 0.8 nnn. Fourth femur, 0.4 mm; ])ate]]a and tibia, 0.5 
mm; metatarsus, 0.2 nnn; tai-sus, 0.2 mm. 

Diagnosis. The shape of the carapace (Fig. 2) and color of 
the abdomen separate P. ntoyohamha from P. ruhroniaculata. 
The palpus (Fig. 1) has a shorter embolus than P. longiceps. 
The palpus resembles that of some species of Dipocna, but only 
determination of the number of female seminal receptacles will 
make the generic affiliation certain. 

Phoroxcidia studo sp. n. 
Figures 6-11 

Type. Female holotype from Sao Paulo de Olivenca, Ania- 
zonas, Brazil (M. de Mathan), in the Museum National d'llis- 
toire Naturelle, Paris (No. 8329). The specific name is an arbi- 
trary combination of letters. 

Description. Carapace dark brown with posterior central por- 
tion lighter brown ; sternum, legs dark brown. Abdomen dark 
brown, sclerites darker, a Avliite pigment ring around lateral 
edge on venter (Figs. 9, 10), and some white pigment spots be- 
hind epigynum. Carapace tuberculate on sides. Median eyes on 
projection and each two lateral eyes on a tubercle (Fig. 6). 
Anterior median eyes slightly larger than others, their diameter 
apart. Posterior median eyes their diameter apart. Dorsum of 
abdomen with trapezoidal sclerites, venter also with sclerites 
(Figs. 9-11) . ^lost sclerites with darker spot in middle and double 
bordered. Total length 2.1 mm. Carapace 0.9 mm long, 0.7 mm 
wide. First patella and tibia 0.5 mm ; second 0.4 mm ; third, 0.4 
mm. Fourth femur, 0.6 mm ; patella and tibia, 0.6 mm ; meta- 
tarsus, 0.3 mm; tarsus, 0.3 mm. 

Diagnosis. The unusual shape and arrangement of the sclero- 
tized plates readily separate this species from all other PJwron- 
cidia. I suspect that this is the female of Phoroncidiu longiceps. 
known only from a male. A juvenile male collected in Peru has 
its abdomen like that of the female but the mc^dian eye region 
projects farther anteriorly. 

Records. Peru. Hiianiico: Divisoria, Sept., Oct. 1946, 1 juv. 
S (F. Woytkowski, AMNH). Brazil. Amazonas. Sao Paulo de 
Olivenca, 9 paratype (M. de ^Mathan, MNIIN). 



72 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Phoroncidia longiceps (Keyserling), n. comb. 
Figures 12-17 

Wibrada longiceps Keyserling, 1886, Die Spiiinen Amerikas, Tlieridiidae, 
2(2): 22, pi. 11, fig. 145, $. Male holotype from "Peru," in the Mu- 
seum National d'Histoire Naturelle, Paris, examined. 
Vibrada longiceps, — Simon, 1894, Histoire Naturelle des Araignees, 1 : 
560, fig. 570. 

Note. Keyserling 's locality is in error since the specimen is 
marked as coming from Le Para [Belem, Brazil] and was col- 
lected by M. de Mathan. Simon (1894) indicated that the speci- 
men came from the Amazon region of Brazil. Keyserling ap- 
parently misread Peru for Para on the label. 

Bescripiion. Carapace dark brown, the portion covered by 
abdomen lighter. Sternum, legs dark brown. Dorsum of abdo- 
men dark brown ; venter with selerotized areas dark brown but 
a ring of white pigment between dorsal and ventral scuta 
(Figs. 15, 16). Carapace tuberculate on sides; sternum tubercu- 
late. Anterior median eyes slightly larger than others, their 
diameter apart. Posterior median eyes their diameter apart. 
Median eyes projecting (Figs. 12, 13), and laterals on a hump. 
Chelicerae with small fangs. Abdomen with a dark dorsal shield 
that has impressions of trapezoids; in the center of each is a 
dark spot (Figs. 15, 17). Total length 1.6 mm. Carapace 0.9 
mm long, 0.7 mm wide. First patella and tibia, 0.4 mm ; second, 
0.3 mm ; third, 0.3 mm. Fourth femur, 0.5 mm ; patella and 
tibia, 0.5 mm ; metatarsus, 0.2 mm ; tarsus, 0.2 mm. 

Judging by the trapezoid dorsal impressions and the trapezoid 
plates on dorsum of the abdomen, P. siiido may be the female of 
P. longiceps. 

Phoroncidia rubromaculata (Keyserling), n. comb. 
Figures 21-23 

Herihertus ruhromaculatus Keyserling, 1886, Die Spinnen Amerikas, Tlieri- 
diidae, 2(2): 28, pi. 11, fig. 148, $. Fragments of male type from 
[Nova Friburgo, Est. Eio de Janeiro] Brazil, in the Museum National 
d'Histoire Naturelle, Paris, examined. 

Ulesanis rubromaculata, — Simon, 1894, Histoire naturelle des Araignees, 
1: 554. 
Note. Keyserling described the species from "Brazil." The 

label in the type vial indicates that the specimen came from 

"N. Friburgo." Both palpi and most legs of the holotype are 

missing. 



LEVI: AMKincAX I 'HOK'ONM IDIA 73 

Description. Carapace d;irk hi'owii. Sicrnuiii. Ic^-s brown. 
Selerotized ]nirt of abdomen bi'owii, dorsum with a median white 
mark, Avliich is longer than wide and was pr()l)ably i-eddisli in 
the live spider (Fig. 23). Eyes subequal in size. Antei-ior me- 
dian eyes one and one-half diameters apart, two and one-lialf 
diameters from laterals. Posterior median eyes one and one-half 
diameters apart, one and thi'ee-(iuarters diameters from laterals. 
Eye region of carapace high and projecting anteriorly (Fig. 
21). Abdomen with heavily selerotized dorsal shield having 
some darker marks. Venter with numerous selerotized areas 
(Figs. 21, 22). Total length 2.1 mm. Carapace 1.0 mm h)ng, 
0.8 nun wide. First femur, 0.7 iiini. Second patella aiul tibia. 
0.5 mm. 

PnoRONCiDiA scuTULA (Nicolet), n. comb. 
Figures 18-20 

(htstcracantha scutuJa Xicolot, 1849, ('« Gay, Histoiia de Cliile, Zool., 10(3): 

•i78, pi. 5, fig. 6, ? . Female type from Chile lost. 
Gasteracantlia caduceator Nicolet, 1849, op. cif., p. 479. Female type from 

Chile, lost. 
Gasterucantha violaccata Xit-olet, 1849, op. cit., p. 479. Female type from 

Chile, lost. 
Gasteracantlia porcellanac Xicolet, 1849, op. cit., p. 480. Female type from 

Cliile, lost. 
Gasteracantlia maculata Xicolet, 1849, op. cil., p. 480. Female type from 

Chile, lost. 
Gasteracantlia rcnusta X'icolet, 1849, op, cit., p. 480. Female type from 

Chile, lost. 
Gasteracantlia ventrosa Xicolet, 1849, op. cit., yi. 481. Female type from 

Chile, lost. 
Gasteracantlia scitida Xicolet, 1849, op. cit., p. 481. Female type from 

Chile, lost. 
Gasteracantlia inflata Xicolet, 1849, op. cit., p. 482. Female type from 

Chile, lost. 
Gasteracantlia columnata X'icolet, 1849, op. cif., p. 482. Female type from 

Chile, lost. 
Gasteracantlia punclata Xicolet, 1849, op. cil., p. 483. Female type from 

Chile, lost. 
Gasteracantlia minuta Nicolet, 1849, op. cit., j). 483. Female type from 

Chile, lost. 
Ulesanis scutula, — Keyserling, 1886, Die Spiniien Amerikas, Theridiidac. 

2(2) : 18, pi. 11, fig. 14, 9. — Tullgren, 1902, Bih. Svenska Yet. Akad. 

Handl., 28(4): 16, fig. 5, i. Bonnet, 19r)9, Bibliograpliia Araiioorum, 

2:4753. 



74 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 

Note. Keyserling first synonymized Nieolet's Gasteracantha 
species. According to Keyserling the abdomen of the female is 
like that of the male. 

Description. Male. Carapace dark grayish brown. Distal end 
of labium and maxillae white. Sternum dark gray-brown. Legs 
dark brown except coxae and tarsi white. Abdomen black with 
white spots on dorsum or sides, no two specimens alike. Sclero- 
tized parts very dark brown. Carapace highest in thoracic re- 
gion (Fig. 19). Anterior median eyes slightly larger than 
others, their diameter apart and one diameter from laterals. 
Posterior median eyes two-thirds diameter apart, one and one- 
quarter diameters from laterals. Abdomen dorsum covered by a 
sclerotized, punctate scutum, with a dorsal hump (Figs. 19, 20). 
Sclerotized plates and spots on sides ; epigastric area heavily 
sclerotized and sclerotized ring around spinnerets. Total length 
1.8 mm. Carapace 0.9 mm long, 0.8 mm wide, 0.4 mm high. 
First patella and tibia, 0.6 mm ; second, 0.5 mm ; third, 0.4 mm. 
Fourth femur, 0.6 mm ; patella and tibia, 0.7 mm ; metatarsus, 
0.3 mm ; tarsus, 0.3 mm. 

Older males have the abdomen more wrinkled ventrally than 
younger ones. 

Records. Bolivia. Beni: Rurrenabaque, 10 Nov. 1956, $ (L. 
Peiia, ISNB). Chile. Valdivia: Enco, 3 March 1955, $ (L. 
Peiia, ISNB). Llanquihue: Carelmapu, 21-28 Feb. 1961, $ (L. 
Pena, ISNB). Aysen: Upper part of Aysen Valley, $ (P. Du- 
sen, RMS). 

Phoroncidia AMERICANA (Emcrtou) 
Map 

Ulesanis americana Emerton, 1882, Trans. Connecticut Acad. Sci., 6: 28, 
pi. 6, fig. 1, 9 , $ . Female, male syntypes from New Haven, Connec- 
ticut, in the Museum of Comparative Zoology, examined. — Bonnet, 
1959, Bibliographia Araneorum, 2:4751. 
Oronota americana, — -Levi, 1955, Ann. Ent. Soc Amer., 48; 334, figs. 1-8, 
?, $. 
Distribution. Eastern Canada, eastern United States, Cuba, 
Jamaica. (Map.) 

Adclitional Records. Canada. Nova Scotia: Coldbrook, 31 
Aug. 1955 (C. Dondale). Ontario. ]\Iarten River, 36 mi. N of 
North Bay, 31 Aug. 1955 (II., L. Levi). United States. Michi- 
gan. Crawford Co.: Hartwick Pines, Sept. 1955 (II., L. Levi). 



I.KVI : AMKKICAX IM I()R( )X(II)|.\ 



75 



Arkansas. Washino:toii Co.: Cove Creek \';illcy, 15 mi. W of 
Prairie Grove; Boston Mts., 300 m (0. llitej. Jamaica: Ilai-d- 
war Gap, 5 Dec. 1954, $ (A. M. Nadler, AMNIT). 




Distriljution of Pltoroncidia antrriccnia. 



PhORONCIDIA NICOLETI sp. 11. 

Figures 24-26 

Type. Male holotype from Sierra cle Chilian, Chilian, Chile, 
in the Museum National d'Histoire Naturelle, Paris (no. 17()99). 
The species is named after the early French arachnologist H. 
Nieolet. 

Descripfioit. Carapace brown with indistinct pray marks 
radiating- to sides. Sternum brown. Legs brown with distal seg- 
ments lighter. Abdomen dark gray with a narrow dorsal light 
crescent, underlain by white pigment, with its arms pointing 
posteriorly (Fig. 26). Ring around spinnerets darker gray. 
Carapace only slightly overhanging eye region. Eyes subequal 
in size. Anterior eyes their diameter apart. Posterior medians 



76 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

one and one-quarter diameters apart, two-thirds diameter from 
laterals. Abdomen Avith two posterior pointing projections (Figs. 
25, 26), cornicnlate, except for smooth area of white crescent. 
Total length 1.6 mm. Carapace 0.7 mm long, 0.7 mm wide. 
First femnr, 0.7 mm ; patella and tibia, 0.6 mm ; metatarsus, 0.4 
nnii ; tarsus, 0.3 nnn. Second patella and tibia, 0.5 mm; third, 
0.4 nnn; fourth, 0.6 mm. 

Diagnosis. The two projections of the abdomen (Figs. 25, 
26) distinguish this species from P. scufida, and the lack of 
dorsal tubercles from P. coquimo. 

Phoboncidia ravot sp. n. 
Figures 27-29 

Type. Male holotype from Tovar, Aragua, Venezuela, 1888 
(E. Simon), in the Museum National d'Histoire Naturelle, Paris 
(no. 10171). The specific name is a noun in appo.sition, an ana- 
gram of the type locality. 

Description. Carapace dark brown, sternum brown, legs yel- 
low-brown. Abdomen dark brown except for two pairs of white 
spots on dorsum, a large white patch on each side above spin- 
nerets, and a white patch on each side of the venter anterior 
to pedicel above carapace. Carapace with median eyes on pro- 
jection and laterals on a slight hump. Eyes subequal in size. 
Anterior median eyes one diameter apart. Posterior median eyes 
one and one-half diameters apart, about three diameters from 
posterior laterals. Abdomen subtriangular with a median dor- 
sal posterior spine (Figs. 27, 29). Dorsum covered with in- 
numerable small sclerotized discs ; some elongate plates on 
ventral part of sides and venter with some round plates and 
spots between epigastric groove and sclerotized ring surround- 
ing spinnerets. Total length 2.0 mm. Carapace 1.0 mm long, 
0.8 mm wide. First patella and tibia, 0.6 mm ; second, 0.4 mm ; 
third, 0.4 mm. Fourth femur, 0.6 mm ; patella and tibia, 0.6 
mm ; metatarsus, 0.3 mm ; tarsus, 0.3 mm. 

Diagnosis. The well-sclerotized palpus has the embolus al- 
most straight, unlike any other Phoroncidia examined (Fig. 28). 
It is possible that this is the male of P. gira collected at the 
same locality, and having a triangular abdomen. 

Records. Venezuela. Aragua: Tovar, 2 juv. paratvpes, 1888 
(E. Simon, MNHN). 



LKVI : AMKHICAX I'l lOKO.XCIDIA 77 

PlIOHONCIDIA MARGAMARGA Sp. II. 

Figures 30-34 

Type. Female holotypc from Marga. Maf^vi, \'alparaiso Prov., 
Chile, 11-13 Sept. 1054 ( L. Pcna), in the liistitnt Poyal des 
Sciences Xalurellcs de B('l^i({iie, Brussels. Tlic six-cific name is 
a noun in apposition after the type locality. 

Description. Carapace dark brown, eye r('<iioii yellowish 
white. Chelicerae, sternum yellow-white. Legs yellow-white, ex- 
cei)t fourth femur with a distal brown ring; all tibiae with a 
distal dark brown ring. Abdomen with scattered gray and black 
pigment, sclerotized spots over muscle attachment black, and 
two longitudinal parallel lines of black pigment spots (Fig. 34). 
Venter of abdomen with scattered gray pigment and three l)lack 
spots on each side of sclerotized ring around spinnerets. Eyes 
subecjual in size, anterior medians slightly less than theii- di- 
ameter apart, and slightly less than their diameter from lat- 
erals. Posterior median eyes one-third diameter apart, one and 
one-half diameters fi'om laterals. Abdomen wrinkled and with 
humps (Figs. 32-34). Total length of female 2.7 nun. Carapace 
0.6 mm long, 0.8 mm wide. First patella and tibia. 0.7 mm; 
second, 0.6 nun; third, 0.6 nnn. Fourth femur, O.i) mm; iiatella 
and tibia, O.i) mm; metatarsus, 0.5 mm; tarsus, 0.4 mm. 

Diagnosis. The abdomen shape (Figs. 32-34) distinguishes 
this species from other Phoroncidia. The epigynum shows no no- 
ticeable structure. The lateral dark spots are muscle attach- 
ments. The internal ducts are so transparent that they were 
invisible on the single specimen examined. The indistinct open- 
ing, however, seems to be in the center. 

Phoroncidia coquimbo sp. n. 
Figures 38-41 

Type. Female holotype from Hacienda Illapel, 600-1300 m 
elev., Coquimbo, Chile, 24-31 Oct. 1954 (L. Pena), in the In- 
stitut Koyal des Sciences Naturelles de Belgique, Brussels. The 
specific name is a noun in apposition after the province of the 
type locality. 

Description. Carapace dark brown, lightei- in middle and 
behind. Sternum brown with a narrow darker l)order. Legs 
yellow-brown, proximal end and distal half of femora, patellae 
and distal half of tibiae brown. Abdomen reddish brown, black 
on each side, some black iiigment aci'oss middh^ and on lateral 



78 BL'LLETIX : MUSETTM OP^ COMPARATIVE ZOOLOGY 

extensions ; white pigment spots around each nipple and on 
dorsum of each lateral extension. Venter reddish brown, darker 
around spinnerets; a white spot on each side of the epigastric 
area (Figs. 40, 41). Eyes subequal in size. Anterior median 
eyes two-thirds diameter apart, three-quarters diameter from 
laterals. Posterior median eyes three-quarters diameter apart, 
one and one-quarter diameters from laterals. Abdomen wider 
than long with four dorsal nipples in a longitudinal row and 
two lateral posterior extensions (Fig. 41), many small sclero- 
tized discs and numerous small sclerotized spots all over abdo- 
men. Sclerotized ring around spinnerets. Total length 3.0 mm. 
Carapace 0.8 mm long, 0.9 mm wide. First patella and tibia. 
0.6 mm ; second, 0.6 mm ; third, 0.5 mm. Fourth femur, 0.8 mm ; 
patella and tibia, 0.8 mm; metatarsus, 0.4 mm; tarsus, 0.3 mm. 
Diagnosis. The selerotization of the abdomen is lighter than 
in other species of Phoroiicidia. The shape of the abdomen 
(Figs. 40, 41) is distinct. The epigynum has an indistinct me- 
dian opening (Fig. 39) ; the two seminal receptacles are spheri- 
cal (Fig. 38). The course of the ducts remains uncertain. 

PnORONCIDIA TINA Sp. 11. 

Figures 35-37 

Type. Male holotype from Diamantina, ]\linas Gerais, Brazil, 
1902 (E. Gounelle) in the Museum National d'Histoire Natur- 
elle, Paris (no. 22462). The specific name is an arbitrary com- 
bination of letters. 

Description. Carapace yellow with a median thin longitu- 
dinal black line ; area between eyes black. Sternum yellow. Legs 
yellow; fourth darkest, In-ownish. Abdomen dorsum silver with 
sclerotized discs yellow, giving it a golden appearance. Sides of 
abdomen silver ; venter black except for silver spot between epi- 
gastric groove and dark ring around spinnerets. Carapace with 
eye region projecting (Fig. 36). Anterior median eyes larger 
than other eyes, one-third their diameter apart, almost touching 
laterals. Posterior eyes less than their diameter apart. Abdo- 
men with five dorsal thorns (Figs. 36, 37). First leg with spines 
on ventral tibia and one on distal end of metatarsus. Sclerites 
of palpus weakly sclerotized. Total length 2.1 mm. Carapace 
0.9 mm long, 0.9 mm wide. First femur, 1.1 mm; patella and 
tibia, 0.9 mm ; metatarsus, 0.5 mm ; tarsus, 0.4 mm. Second pa- 
tella and tibia, 0.7 mm; third, 0.5 mm; fourth, 1.0 mm. 



i.i;vi : AMi;iJi(Ax i'iioi;()X(ii)iA 79 

Diagnosis. This is llic only Aiiirricaii species of I'horoncidid 
liavinjr fi\c dorsal spines (Fi^'s. ;}6, :J7). This specimen was in 
tlie vial with two female /'. hioccllata, but is believed to be a 
se|)ai-ate species. 

P]ioi{()X(ii)iA sci'i i:i,i.AM A ( Taczanowski ). n. comb. 
Fiuuivs 42-45 

TrirantJia scnhJJata Taczanowski, (1879) 1880, Ilorae Soc. Eiit. Rossicae, 
15: 12:2, pi. 1, fig. 3.5. Female holotype from Amable Maria, [prov. 
Tnriua, .Tviiuiij, Peru, in tlie Polisli At-ademy of Sciences, Warsaw, 
examined. 
Description. ('ai'a])ace ycllow-hi-ow n. head rciiioii li'jhtei', 
stcrnniii. Ic^s ycllow-hi'owii. Alidouicn with white |)iL;iii<'nt on 
(loi-sum ; tip of j)osterior spine orange and scleroti/ed discs 
brown. Sides of venter with white pigment, most of venter bare 
ol' pigment. s(d('rotize(l areas broAvn. Eyes snbeqnal in size. An- 
terior median eyes one diameter apart, one and one-half di- 
ametei-s from laterals. Posterior median eyes a little more than 
thcii- diameter apart, almost two diameters from laterals. 
Stenium slightly i)nnctate. Abdomen relatively small, shield- 
shaped with a median dorsal posterior spine (Figs. 44, 4;")). To- 
tal length 2.0 mm. Carapace LO mm long, 1.1 nnn wide. First 
])atella and tibia. 0.8 mm; second, O.G nnn; third, OJi mm. 
Fourth femur. 0.9 mm; patella and tibia, 1.0 nnn; metatarsus, 
0.5 nnn; tarsus, 0.4 mm. 

PnoROXciDiA CRiBRATA (Simon), n. comb. 
Figures 52-56 

Trithena cribrata Simon, 189.3, Ann. Soc. ent. France, 02: 32:'., ]il. 7, fis- 5, 
2. Female holotype from Paraguay in the ]\[nseum Xatioiial il'Ilis 
toire Natiirelle, Paris, examined. 
Description. Carapace brown, darker on sides; stei-nnm y<'l 
low-brown. Legs yellow-brown, fourth darkest. Abdomen whit( 
except for an unpigmented area on each side of pedicel (Fig. 
55), three orange to dark brown spines, large dark brown anr" 
smaller brown sclerotized spots, and dark brown epigyinim and 
spinneret area. Eyes suliecpial in size. Anterior median eye 
one diameter apart, one and one-third diameters from laterals. 
Posterior median eyes one diameter apart, two diameters fror' 
laterals. Abdomen with three spines but more s|)liei-i('al in shapr 
than I'elated species, and with many small sclci'ot IzimI spot; 



80 BTTLLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

(Figs. 54-56). Total length 4.9 mm. Carapace 1.3 mm long, 1.1 
mm Avide. First patella and tibia, 0.9 mm; second, 0.7 mm; 
third, 0.7 mm. Fourth femur, 1.1 mm; patella and tibia, 1.2 
mm ; metatarsus, 0.4 mm ; tarsus, 0.4 mm. 

Diagnosis. The epigynum has two separate openings in a 
common, central, heavily sclerotized depression (Fig. 53). The 
spines are shorter than those of related species. 

PiiORONcnuA TRicusPiDATA (Blackwall), n. comb. 
Figures 46-51 

Ph'ctana iricuspidaia Blackwall, 1863, Aim. Mag. Nat. Hist., (3) 11: 38. 
Female holotype from Eio de Janeiro, Brazil, in the Hope Department 
of Entomology, Oxford University, examined. 

Trieaiitha trlcornis Simon, 1864, Histoire Naturelle des Araignees, 1 edit., 
p. 293, fig. 136, 9 ; nomen nudum. From Brazil. 

Tricantha inuncans Simon, 1867, Rev. IMag. Zool., (2) 19: 23. Female holo- 
type from Nova Friburgo, [Est. Eio de Janeiro], Brazil, in the Mu- 
seum National d 'Histoire Naturelle, Paris, examined. This specimen 
has an insect pinhole througli the epigynum. 

Di'scripiion. Female holotype of P. fricuspidafa: carapace, 
sternum, legs yellow-brown. Dorsum of abdomen white, three 
spines orange. Both the type of T. inuncans and the specimen 
from Teresopolis without dorsal pigment. Venter of abdomen 
without ])ignient except for white on each side of pedicel and 
ringing spinnerets up to genital groove ; an unpigmented streak 
up each spine. Eyes subequal in size, posterior median eyes 
slightly smaller than others. Anterior median eyes less than a 
diameter apart, one diameter from laterals. Posterior median 
eyes one diameter apart, two diameters from laterals, ("heli- 
eerae with two anterior teeth. Abdomen with three spines, dor- 
sum with large round sclerotized plates of variable size (Figs. 
50, 51), and some few small sclerotized spots. Epigynum with 
slits, very difficult to discern in most specimens (Fig. 47). To- 
tal length 5.5 mm. Carapace 1.4 mm long, 1.4 mm wide. First 
patella and tibia, 1.1 mm; second, 0.8 mm; third, 0.7 mm. Fourth 
femur, 1.2 mm; patella and tibia. 1.4 mm; metatarsus, 0.6 mm; 
tarsus, 0.5 mm. 

The holotype of T. inuncans has larger paired dorsal discs 
(Fig. 51) than the holotype of P. tricuspid at a (Fig. 50). 

Records. Brazil. Est. Rio dr Janeiro: Teresopolis, 9 
(MNIIN) ; :\lan-li 1946, 9 (II. Sick, AMNH). 



LEVI : AMERICAN PIIOK'OXt IDIA 81 

PlIOROXCIDIA FLAVOLIMBATA (Sillion), 11. COinb. 

Figures 57-61 

Trica/itha ffdvolimbata Simon, 1893, Ann. Hoc. cut. Fr;mcc, (12: 322, pi. 7, 
fiK. 3. Female holotyjie from Lo.ja, Ecuailor, in the .Nrnseum National 
d'Histoirc Xatiirellc, Paris, cxaniineil. 

Description. Carapace yellow-brown, black in immediate area 
around anterior median eyes and between lateral eyes. Sternum 
dark brown; legs yellow. Abdomi'n white except for golden yel- 
low spines, dark brown sclerotized spots, and minute scattered 
orange si)ots on dorsum. Epigynum dark brown and area 
around spinnerets also dark brown. Eyes subetjual in size. An- 
terior median eyes one diameter apart, one and one-third di- 
ameters from laterals. Posterior eyes one and one-half diameters 
apart. Abdomen widest anteriorly with three spines, and hav- 
ing sclerotized spots on dorsum and venter (Figs. 59-61). Total 
length 5.9 mm. Carapace 1.2 mm long, 1.3 mm wide. First 
patella and tibia, 1.1 mm; second, 0.8 mm; third, 0.8 mm. 
Foui-th femur, 1.8 nun; patella and tibia, 1.8 mm; metatarsus, 
0.7 nun ; tarsus, 0.5 mm. 

Diagnosis. The epigynum has the openings near the posterior 
border, at the lateral ends of a transverse groove (Fig. 58). 

PlIOROXCIDIA BiocELLATA (Simou), n. comb. 
Figures 67-71 

Tricantha hiocellaia Simon, 1893, Ann. Soc. ent. France, 62: 323, pi. 7, 
fig. 4. Female leetotype here designated from Cara^a, Minas Gerais, 
Brazil, in the Museum National d'Histoire Naturelle, Paris, examined. 

Description. Carapace, sternum, legs yellow-brown. Abdo- 
men Avith less white pigment than in some related species (Fig. 
71), spines orange to black. The paratype has more white pig- 
ment than the leetotype. The epigynum and the ring around 
spinnerets dark brown. Eyes subequal in size. Anterior median 
e.yes slightly less than one diameter apart, slightly less than two 
diameters from laterals. Posterior median eyes one and one- 
quarter diameters apart. Two diameters from laterals. The 
paratype, although mature, is much smaller than the leetotype. 
being only 3.7 mm total length. Total length of leetotype 4.8 
mill. Carapace 1.2 mm long, 1.1 mm wide. First patella an(^- 
tibia, 1.0 mm; second, 0.6 mm; third, 0.6 mm. Fourth femur. 
1.0 mm; patella and tibia, 1.2 iiiiii; metatarsus, 0.6 mm; tarsus. 
0.4 mm. 



82 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Diagnosis. Abdomen less sclerotized than in related species, 
having only large sclerotized discs but no small spots on dorsum 
(Figs. 69, 71). Epigynum openings are indistinct slits (Fig. 
68) ; connecting ducts (Fig. 67) transparent. 

Record. Brazil. Minas Gerais: Diamantina. 1902, 2 9 (E. 
Gounelle, MNHN) ; Caraca, 9 paratype (E. Gounelle, MNHN). 

Phoroncidia triunfo sp. n. 
Figures 62-65 

Trlcnntha tricornis, — F. P.-Caniltridge, 1904, Biologia Centrali-Americana, 
Araneidea, 2: 540, pi. 51, fig. '26, $. Not Tricaniha tricornis Simon. 

Tijpe. A damaged female holotype from El Triunfo, Chiapas, 
Mexico, 2000 m alt., April 1942 (H. Wagner), in the American 
Museum of Natural History. The specific name is a noun in 
apposition after the type locality. 

Descripfioi). Carapace brown. Sternum lighter brown. Legs 
brown. Dorsum of abdomen white, sclerotized spots brown, three 
spines orange. Venter whitish Avith brown epigynum and ring 
around spinnerets. Eyes subequal in size ; anterior median eyes 
one diameter apart, one and one-half diameters from laterals. 
Posterior median eyes one diameter apart, two diameters from 
laterals. Abdomen (Figs. 64, 65) with three spines, paired dor- 
sal sclerotized discs and small sclerotized spots. Total length 4.6 
mm. Cara})ac(' 1.3 mm long, 1.3 nun wide. First patella and 
tibia, 1.2 mm; second, 0.8 mm; third, 0.8 mm. Fourth femur, 
1.3 mm; patella and tibia, 1.4 iiuii ; metatarsus. 0.8 unii ; tarsus, 
0.5 mm. 

Diagnosis. Epigynum, witli two separate ojxmings in a flat 
area anterior to a keel (Fig. 63), distinguishes this species from 
/'. tricuspidata and P. vribraia. 

Records. Mexico. Colima: Nevada de Colima, 21 Jan. 1943, 
juv. (F. Bonet, AMNH). Chiapas: El Triunfo, 2000 m, April 
1942, fragments of 2 9 paratypes (II. Wagner, AMNH). Giia- 
t()iial((. Motaila de Chilasco (F. P. -Cambridge, 1902). Cost a 
Rica. Tablazo, juv. (Tristan). 

Phoroncidia saboya sp. n. 
Figures 72-76 

Typ(. Female liolotype from ''Cabin La Luzera," Saboya, 
Poyaca, Coloiiihia, in the Hi-itish Museniu. The specific name is 
i\ iionn in jipposition ;irt<'r the type locality. 



LKVI : AMKRKAX IM lOROXCIDI A 83 

Descripf i'ui. Tlic type is in jxioi- physical (M)ii(lil ion, liaviii^- 
oriji-iiially hccii pitiiicd and dried. Cafapacc, stcrmiiii, Icus yci- 
l()\v-bi'()\vii. Ahdoiiicn with spines oi'ang'e-wliite ; sides and an- 
lei'ioi- (if ddi-snm white and middle with scattered white i)igmeiit ; 
sch'roti/A'd phites and smaller spots lijilit br-own. Venter with 
some scattei-ed white pig'ment spots, sides white. Anterior me- 
dian eyes veiy slightly larger than othei's, one and one-(piartei- 
diametei's aj)art, two diametei's from laterals. Posterior median 
eyes one and thi-ee-cpiarters diameters apart, two diameters from 
laterals. Abdomen (Figs. 74-76) with three large spines and 
dorsum with j)aired round plates and scattered smaller selero- 
tized spots. S])ines less sclerotized than in related species. To- 
tal length 5.5 mm. (^^ara])ace 1.5 mm long, 1.8 nun wide. First 
patella and tibia, 1.4 nun; second, 1.2 mm; third. 1.1 mm. 
Fourth femur, 1.7 mm; ])atella and tibia, 1.4 mm; metatarsus, 
0.9 mm ; tai'sus, 0.6 mm. 

Dimjuosls. The base of the abdominal spines is wider (Figs. 
74-76) than in related species. The epigynum differs from P. 
triunfo and others by having two indistinct dark spots contain- 
ing the openings, and between and anterior to the spots a deep 
V-shaped groove (Fig. 73). 

PlIOROXCIDIA REIMOSERI sp. n. 

Figures 77-81 

Type. Female holotype from Est. Rio Grande do Sul, 1908, 
Brazil (E. Reimoser), in the Museum of Comparative Zoology. 
The species is named after its collectoi-, the arachnologist E. 
Reimoser. 

D( scripfiou. Carapace, sternum shiny dark brown. Legs 
lighter brown, distal portion of fourth femoi-a, and foui'th pa- 
tellae darker. Abdomen with spines shiny black, dorsum yellow- 
white in alcohol ; venter white proxinuil to spines ; sid(>s and 
posterior black; a dark brown ring around spiinierets and white 
between. Anterior median eyes slightly larger than others; two- 
thirds diameter apart, two diameters from laterals. Posterior 
median eyes one and one-half diameters apart, two diameters 
from laterals. Abdomen with three spines (Figs. 79-81), sclero- 
tized discs, and variable nnmbei- of tiny sclerotized spots. Total 
length of females 3.3-5.0 nun. Total length of one female 4.6 
mm. Carapace 1.3 mm long, 1.3 mm wide. First ])atella and 
tibia. 1.0 mm; second. 0.8 mm; third, 0.7 mm. Fourth femur, 



84 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

1.1 mm; patella and tibia, 1.3 mm; metatarsus, 0.6 mm; tarsus, 
0.5 mm. 

Drawings Avere made from a recently collected specimen from 

Nova Teutonia. 

Diagnosis. The single median opening in the epigynum (Fig. 
78) distinguishes the species from P. tricuspidata. 

Records. Brazil. Est. Sao Paulo: Fazienda Novo-Niagara, 
lat 23° 00' S, long 49° 20' W, 1898, 9 (E. Gounelle, MNHN). 
Santa Catarina: Nova Teutonia, lat 27° 11' S, long 52° 23' W, 
? (F. Plaumann, SMF). 

Phoroncidia gira sp. n. 
Figures 82-86 

Tifpe. Female holotype from Tovar, Aragua, Venezuela, 1888 
(E. Simon) in the Museum National d'Histoire Naturelle, Paris 
(no. 10025). The specific name is an arbitrary comliination of 
letters. 

Description. Carapace, sternum brown, legs lighter brown. 
Abdomen with three orange-colored spines, dorsum white except 
for dark brown sclerotized discs and spots; venter white on 
sides, but area between epigynum and spinnerets on sides of 
pedicel without pigment. Eyes subequal in size. Anterior me- 
dian eyes one diameter apart, one and one-half diameters from 
laterals. Posterior median eyes one and one-cjuarter diameters 
apart, two diameters from laterals. Abdomen with three spines, 
large, dark discs and smaller sclerotized spots on dorsum and 
venter. Total length 5.7 mm. Carapace 1.3 mm long, 1.4 mm 
wide. First patella and tibia, 1.0 mm; second, 0.5 mm; third, 
0.5 mm. Fourth femur, 1.3 mm; patella and tibia, 1.3 mm; 
metatarsus, 0.6 mm ; tarsus, 0.5 mm. 

Diagnosis. The epigynum has a posterior median dark de- 
pression with an indistinct dark spot in each side of it (Fig. 
83). The region posterior to the depression is heavily sclerotized. 
The connecting ducts are hardly visible in the cleared female 
genitalia (Fig. 82). The structure on the epigynum and the 
relatively long abdominal spines se]iarate the species from P. 
triunfo and /*. tricuspidaia. 

KEFERENCES 

Hickman, V. V. 

1951. New I'horoncidiinao and the afliiiitios of the Now Zealand 
spider Atkinsonia ikiiki ('aiiiliridg'e. Paiu'is Proc. Roy. Soe. 
Tasmania. 1950: 3-'J4. 



LEVI: AMERICAN PIIOROXCIDIA 85 

Levi, H. W. 

1955. The spider genera Oronota and Sttiitinoji.s in North America, 
Central America and the West Indies (Araneae, Theridiidae). 
Ann. Ent. Soe. America, 48f.l): 333-342. 
Levi, H. \V. and L. R. Lfai 

19(5:2. The genera of the spider- family Theridiidae. Bull. .Mas. Conip. 
Zoul., 127(1): 1-71. 

(lieceived May 13, 19G3.) 



86 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



INDEX 

Valid names are printed in italics. 



albopum-tata, Trieantha, (59 
aniericana, Oronota, 74 
americana, PJioroncidiii, 74 
anierieana, Ulesanis, 74 
biocellata Phoroncidia, 81 
biocellata, Trieantha, 81 
caduceator, Gasteracantha, 73 
columnata, Gasteracantha, 73 
coqidmho, Phoroticidia, 77 
cribratci, Phoroncidia, 79 
eribrata, Trithena, 79 
flavolimhafa, Phoroncidia, SI 
flavolimbata, Trieantha, 81 
flavomaculata, Ulesanis, 68 
gira, Phoroncidia, 84 
inflata, Gasteracantha, 73 
inuneans, Trieantha, 80 
longiceps, Phoroncidia, I'l 
longiceps, Wibrada, 70, 72 
maculata, Gasteracantha, 73 
margamarga, Phoroncidia, 77 
niinuta, Gasteracantha, 73 
niojiohaniha, Phoroncidia, 70 



nicoleti, Phoroncidia, 75 
poreellanae, Gasteracantha, 73 
punctata, Gasteracantha, 73 
ravot, Phoroncidia, 76 
reimoseri, Phoroncidia, 83 
ruhromaculaia, Phoroncidia, I'l 
rubroniaculata, Ulesanis, 72 
saboya, Phoroncidia, 82 
scitula, Gasteracantha, 73 
scutelhita, Pltoroncidia, 79 
scutellata, Trieantha, 79 
scutula, Gasteracantha, 73 
scutula, Phoroncidia, 73 
scutula, Ulesanis, 73 
studo, Phoroncidia, 71 
Una, Phoroncidia, 78 
tricornis, Trieantha, 80, 82 
tricuspidata, Phoroncidia, 80 
tricuspidata, Plectana, 80 
triunfo, Phoroncidia, 82 
ventrosa, Gasteracantha, 73 
venusta, Gasteracantha, 73 
violaeeata, Gasteracantha, 73 



PLATES 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



Figs. 1-5. Phoroncidia moyohamha sp. n., male. 1. Left palpus. 2. Cara- 
pace. 3. Lateral view. 4. Abdomen, ventral view. 5. Abdomen and cara- 
pace, dorsal view. 

Figs. 6-11. P. .studo sp. n., female. 6. Carapace. 7. Genitalia, dorsal view. 
8. Epigynum. 9. Abdomen, ventral view. 10. Lateral view. 11. Carapace 
and abdomen, dorsal view. 

Figs. 12-17. P. longiceps (Keyserling), male. 12, 1.3. Carapace. 14. Pal- 
pus. 15. Lateral view. 16. Abdomen, ventral view. 17. Carapace and ab- 
domen, dorsal view. 



LEVI: AMERICAN* IM lOKOXCIDIA 




BULLETIN : MUSEUM OF COMPARATIVE: ZOOLOGY 



Figs. 18-20. Plioroncidia scntula (Nicolet), male. 18. Left palpus. 19. 
Lateral view. -0. Carapace and abdomen. 

Figs. 21-23. P. rubromaculata (Keyserling), male. 21. Lateral view. 
22. Sternum, coxae and aljdonien, ventral view. 23. Carapace and abdomen, 
dorsal view. 

Figs. 24-26. P. nicolcii sp. n., male. 24. Palpus. 25. Lateral view. 26. 
Carapace and abdomen, dorsal view. 

Figs. 27-29. P. ravot sp. n., male. 27. Lateral view. 28. Palpus. 29. Cara- 
pace and abdomen, dorsal view. 



LEVI: AMERICAX rilOROXCIOIA 




BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 



Figs 30-34. PJioroncidia margamarga sp. n., female. 30. Genitalia, dorsal 
view. 31. Epigynuni. 32. Lateral view. 33. Sternum, coxae and abdomen, 
ventral view. 34. Dorsal view. 

Figs. 35-37. F. Una sp. n., male. 35. Left palpus. 36. Lateral view. 37. 
Carapace and abdomen, dorsal view. 

Figs. 38-41. P. eoquimbo sp. n., female. 38. Genitalia, dorsal view. 39. 
Epigynum. 40. Lateral view. 41. Carapace and abdomen, dorsal view. 



LEVI : AMERICAN PIIOROXCiniA 




BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 



Figs. 42-45. Phoroncidia scutellata (Taezanowski), female. 42. Genitalia, 
dorsal view. 43. Epig.viium. 44. Lateral view. 45. Dorsal view. 

Figs. 46-51. P. tricuspidata (Blackwall), female, 46. Genitalia, dorsal 
view. 47. Epigynum. 48. Lateral view. 49. Al)domen, ventral view. 50, 51. 
Carapace and abdomen, dorsal view. 

Figs. 52-56. P. crihrata (Simon), female. 52. Genitalia, dorsal view. 
53. Epigyniim. 54. Lateral view. 55. Sternum, coxae and abdomen, ventral 
view. 56. Carapace and abdomen, dorsal view. 



LEVI: AMKKUAX I'l lOKOXClDlA 






43 



^•^?i",'£5fS3?lK5s-^,, 



53 




BULLETIN : MUSEUM OF COMPARATRTi ZOOLOGY 



rig«. 57-61. Phoroncidia flavolimhata (Simon), female. 57. Genitalia, 
dorsal view. 58. Epigynum. 59. Lateral view. 60. Sternum, coxae and ab- 
domen, ventral view. 61. Carapace and abdomen, dorsal view. 

Figs. 62-65. P. triunfo sp. n., female. 62. Genitalia, dorsal view. 63. Epi- 
gynum. 64. Sternum, coxae and abdomen, ventral view. 65, 66. Carapace 
and abdomen, dorsal view. 65. Adult. 66. Juvenile. 

Figs. 67-71. P. hiocellafa (Simon), female. 67. Genitalia, dorsal view. 
68. Epigynum. 69. Lateral view. 70. Sternum, coxae and alxlomen, ventral 
view. 71. Carapace and abdomen, dorsal view. 



LKVI : AMERICAN I'lIOROXCIDIA 






58 



_;;?*wa>v/;.;'' 'i^!4,' ■ 



63 .••..^;iSS^^fe. 




BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



Figs. 72-76. Phoroncidia sahoi/a sp. n., female. 72. Genitalia, dorsal 
view. 73. Epigynum. 74. Lateral view. 75. Abdomen, ventral view. 76. 
Carapace and abdomen, dorsal view. 

Figs. 77-81. P. reimoseri sp. n., female. 77. Genitalia, dorsal view. 78. 
Epigynum. 79. Lateral view. 80. Sternum, coxae and alidomen, ventral 
view. 81. Carapace and abdomen, dorsal view. 

Figs. 82-86. P. gira sp. n., female. 82. Genitalia, dorsal view. 83. Epi- 
gynum. 84. Lateral view. 8.5. Sternum, coxae and abdomen, ventral view. 
86. Carapace and abdomen, dorsal view. 



i,i;vi : AMi.incAx i'iioi;()X( iDiA 










Bulletin of the Museum of Comparative Zoology 
II A R V A K 1) UNIVERSITY 

Vol. 131, No. 4 



THE BRAINCASE OF THE PALEOZOIC 
ELASMOBRANCH TAMIOBATIS 



By Alfred Sherwood Romer 



With One Plate 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

April 30, 1904 



Publications Issued by or in Connection 

WITH THE 

MUSEUM OF COMPARATIVE ZOOLOGY 
HARVARD UNIVERSITY 



Bulletin (octavo) 1863 — The current volume is Vol. 131 . 

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Occasional Papers of the Department of Mollusks (octavo) 
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The continuing publications are issued at irregular intervals in num- 
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Zoology, Cambridge 38, Massachusetts. 



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Phylogeny and Evolution of Crustacea. Proceedings of a confer- 
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Cloth bound, $6.75. 

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Bulletin of the Museum of Comparative Zoology 

HARVAKU UNIVERSITY 

Vol. 131, No. 4 



THE BRAINCASE OF THE PALEOZOIC 
ELASMOBRANCH TAMI0BATI8 



By Alfred Sherwood Romer 



With One Plate 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

April, 1964 



Bull. Mus. Coiiip. /()()!., llarv.-ird Uiiiv., 131(4 1:87-1(1.'), Ai)ril, 1964 

No. 4 — The Braiiicas( of the ralcozoic Kldsniobranch 
Taiuiobatis 

By Alkhi:i) Siieuwood Ko.mkk 

INTRODUCTION 

Eastman in 1897 described, as Tamiohatis. rrfiisliis, a sjioci- 
mcii fj'oiii Powell Connty, Kentucky, enelosed in a limestone 
nodule, wliicli he heliexcd to exhibit the dorsal surface of the 
braincase of a Devonian skate. However, the age of the specinuui 
is uncertain ; it is not a skate ; it is the ventral, rather than the 
dorsal surface of the braincase that is exposed. In consequence, 
Eastman's structural identifications are quite erroneous. The 
Tamiohatis type is, nevertheless, of considerable importance, for 
it is the best preserved specimen of a Paleozoic elasmobranch 
braincase so far described. A few Paleozoic forms are repre- 
sented by crushed slab materials in which little morpholooical 
detail can be made out. But of three-dimensional Paleozoic shai-k 
braincases, there have been described only two imperfect speci- 
mens. These ar(^ partial, late Devonian braincases, ju'esumably 
of ''Cladodii.s" type (Stensio, 1937; Gross, 1937 ).i 

Some years ago I was struck by the obvious resemblance of 
Tamiohatis to the pleuracanth l)raincases which T was then 
studying'. The specimen (I^SXM No. 1717) was loaned to me 
through the courtes.v of the Division of Vertebrate Paleontology 
of the United States National Museum. In earlier years com- 
plete development of the specimen would have been extremely 
difficult ; thanks, however, to the newer methods of acid prepa- 
ration developed at the British Museum by H. A. Toombs and 
A. E. Rixon, the limestone nodule has l)(>en comj^letely etched 
aAvay Avithout harm to delicate surface sti'uctures of the brain- 
case. Preparation was done Avith the aid of a National Science 
Foundation grant for study of Carboniferous vertebrates. I 
had originally planned to defer description of this specimen 
until after ]niblication of work on the structure (internal as 
well as external) of the pleuracanth braincase. But since it 
currently appears that this study will not be completed for 
some time to come, I am Dublishiug th(^ present account, despite 
the fact that incomplete knowledge of the intenuil structure of 

lA further Paleozoic shark braincaso is (nirrrntlv I)oing stiuliod by Dr. D. II. 
Dunkle of the U. S. National Museum. 



90 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

older elasmobranch braincases may cause misinterpretation of 
the nature of foramina and other external features. 

In the description below I have made no reference to East- 
man's original description, since his belief that the originally 
exposed surface was dorsal rather than ventral invalidates his 
identifications. Thus, for example, the canals for the aortaB are 
identified by him as endolymphatic ducts, the pituitary fossa 
is said to be a dorsal fontanelle, the interorbital region is labelled 
rostrum, and the postorbital and otic processes are described 
as antorbital and postorbital processes, respectively. 

Provenance of the Specimen 

No data concerning the discovery of this specimen have been 
preserved in the records of the U. S. National Museum beyond 
the statement that it was found in the eastern part of Powell 
County, Kentucky. As may be seen from a geological map 
(Jillson, 1929), this small county includes strata ranging from 
Silurian at its western margin to lower Pennsylvanian (Potts- 
ville) on the ridge-tops to the east. However, the stratigraphic 
possibilities can be readily narrowed down. On the one hand, 
the Pennsylvanian beds are continental shales and sandstones, 
and it is practically out of the question that a limestone nodule 
containing marine vertebrates could have been derived from 
them. On the other hand, Silurian and most Devonian beds are 
confined to the western part of the county, and the only De- 
vonian strata reaching the eastern part of Powell County are 
the black shales of the late Devonian, in which (again) occur- 
rence of a limestone nodule of this sort is most unlikely. 

Considerable work in this general area is being done at the 
present time by the U. S. Geological Survey. It is the opinion 
of those familiar with the region that the specimen rather surely 
came from early Mississippian limestones present in eastern 
Powell County. Possibly a closer determination can be made 
when current studies of the region are completed. 

DESCRIPTION 

General. The general appearance of the braincase is readily 
seen in the illustrations. The surface of the cartilage was calci- 
fied to the extent of a millimeter or so. The calcified areas are 
dark in color; over a considerable area of the ventral surface, 
exposed before collection, the calcified material has been eroded. 



ROMKR: TA.MIOBATIS UHAINCASE 



91 



leaving a cast of the uii(lerlyiii<i- I'c^ion occupied by hyaline 
cartila<>e. Such areas are left white in the plat(>. The <i'ciicral 
proportion.s are obvious from cither dorsal or ventral aspects, 
and such structural features as nasal processes, postorbital proc- 
esses, the lonp: otic rcfjion, Avith jii'oinincnt lateral otic i)rocesses. 




Fig. 1. Dorsal view of the braiiu-ase, .sliglitly restored. X V2- Al)l)rcvia- 
tions for tliis and following figures: af, posterior border of anterior fon- 
tanelle; artic, articular facet for palatoquadrate; cc, point of entry of 
"common carotids" into braincase floor; dlof, dorsolateral otic fossa; 
docop, dorsal "opening" in occipital region; dor, dorsal otic ridge; ec?, 
impression of course of external carotid; cfhJ, foramen possibly for efferent 
hyoid artery; endf, endolymphatic fossa; fm, foramen magnum; ic, impres- 
sions of course of internal carotids toward pituitary region; lor. lateral 
otic ridge; ?mcv, foramen probably for middle cephalic vein; nil, openings 
for supraorbital lateral line nerve twigs; np, nasal process; occr, occipital 
crest; op V -\- VII, foramen for ophthalmic rami of nerves V and VII; 
op VII, foramen for ophthalmic ramus of nerve VII; os, optic stalk; 
otpr, otic process; pit, pituitary region (eroded); pop, postorbital process; 
pt VII, canal for pretrematic ramus of nerve VII; r, calcified floor of Ijase 
of rostrum ; rpv, ridge covering posterior part of posterior vertical ear 
canal; sos, subocular shelf; sv-, foramina possibly for somatic nerve twigs; 
unc, uncalcified areas of braincase surface; vcl, foramen primarily for vena 
capitis lateralis; vlof, ventrolateral otic fossa; vos, ventral shelf in otic 
region containing passage for lateral head vein; //, optic foramen; ///. 
oculomotor foramen; IV, trochlear foramen; F, -|- V ^, foramen for inaxil- 
lary and mandibular rami of trigeminal nerve; T',, groove for mandibulnr 
ranuis of trigeminal; VI?, probable foramen for abducens nerve; I'll. 
foramen for main trunk of facial nerve; 7-Y + X, fossa for glossophaiyngeal 
and vagus nerves. 



92 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

and the occipital region, are apparent at first glance. A notable 
contrast with typical modern shark braincases is the long otic 
region. It seems quite certain that the braincase has undergone 
considerable dorso ventral crushing, so that the height (par- 
ticularly in the otic region) is surely much less than Avas the 
case in life. 

Nasal region. Anteriorly, a.s in modern sharks, the roof is 
deeply incised by the curved posterior margin of the anterior 
fontanelle, lying above the cavum precerebrale. Ventrally there 
is preserved, imperfectly, a thin sheet of calcified cartilage 
which represents a rostral structure. From its feeble nature it 
seems certain that the rostrum was short. On either side of the 
fontanelle the upper surface of the braincase extends antero- 
laterally to form a partial roof for the nasal region ; a prominent 
foramen here is obviously for the emergence of the superficial 
ophthalmic ramus of nerve VII, innervating the lateral line 
organs of the snout. 

Nasal capsules are not preserved and were presumably un- 
calcified. A nasal process is completely preserved on the right 
side ; that of the left side is slightly imperfect anteriorly and 
laterally. From the tip of each process a narrow plate of calci- 
fied cartilage descends ventrally and po.steromedially toward 
the floor of the braincase ; this marks the anterior end of the 
plate of calcified cartilage which forms the inner wall of the 
orbital cavity and separates the orbit from intra-cranial areas. 
There is no foramen for an olfactory nerve in the anterior part 
of this plate, and hence this nerve lay medial to it and to the 
nasal process. The contours of the outer surface of this plate 
give no indication of the development of a nasal capsule lateral 
to it. It is hardly possible that the capsules could have been 
situated medially to these plates, filling — or nearly filling — 
the precerebral cavity. It seems reasonable to believe that these 
structures, not improbably essentially spherical in shape, pro- 
jected forward, with the curved surfaces presented by the lateral 
edge of the rostrum and the plates descending from the nasal 
roof marking part of their ventral and lateral margins. 

Orbital region. The braincase roof is very broad and nearly 
fiat between the large orbits. On either side, the roof extends 
outward as a wide shelf, with a smoothly concave lateral out- 
line, over the orbital cavities. A series of small foramina on 
either side allowed the passage of nerve twigs from the ojihthal- 
raic ramus of nerve VII to reach the neuromasts of the supra- 
orbital lateral line canals. 



RO.AlKli: TA.MIOBATIS BKAIXCASE 



93 



Beneath tliis protect iii<i' i-uoi', the ii|)])er jjart of the ()rl)ital 
wall shows a siuootli sweep of its surface from the nasal rejiion 
backward and, finally, outward to the anterioi- surfaet' of the 
postoi'hital process. The superlicial opht lialiiiie ramus of nerve 
VII obviously travelled forward well np beneath the roof (where 
are seen the inner openings of the small foramina for the supr-a- 
orbital lateral line), to reach anteriorly the large foi-aiiieii })\- 
wliich it gained the roof of tiic nasal region. 




viof 



artic VI? 



Fig. 2. Lnk'ral view of the liraiiu-ase, slightly restoroil. Xo attempt has 
been made to correct the marked dorsoveiitral crushing. Alibreviations as 
in Fi(;ure 1. X '^• 



High up, posteriorly, is a large opening, directed anteriorly, 
which is surely for the exit of the ophthalmic rami of the tri- 
geminal and facial nerves. Somewhat anterior and ventral to 
this is a small foramen in the appropriate position for emer- 
gence of the trochlear nerve and, farther ventrally, a somewhat 
larger foramen for the oculomotor nerve. Anteriorly, at about 
this vertical lev;-!, there develops a longitudinal ridge running 
forward toward the nasal region. Below this ridge there is 
present well anteriorly a large foramen, opening anterolatei'ally. 
which is presumably for the optic nerve. A narrow bar back ol' 
this foramen sejiarates it from a long oval opening extending 
back much the length of the orbit not far above the floor. Th(^ 
upper and lower rims of this opening are somewhat everted ; 
its posterior margin is curved strongly outward, and represent:- 
the anterioi- end of a swollen ridge which ]iosteriorly subside: 
into tlie general contours of the cranial wall. The im))i-essior 
gained from this tope ij-raphy is that the opening provided fo'- 
the emergence, anteriorly and laterally, of a cylindr-ieal strue 
ture of some sort — obviously an e.^-e stalk of typical elasmo 
branch type. 



94 



BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 



Openings for an ophthalmic (orbital) artery and a pituitary 
vein would be expected in the ventral part of the orbital cavity. 
I have been unable to make out such openings, presumably be- 
cause of the crushing undergone here by the specimen. 

Posterior to the position of the eye stalk, opposite the base of 
the postorbital process (and hence not seen in lateral view, but 
see Fig. 3A), there is a deep ventral recess, expanding antero- 
laterally from a large foramen. This was obviously for the 
emergence of V2 and V3 as well as, presumably, the lateralis 
nerves for the infraorbital and mandibular lateral line organs. 
Identification of a .small imperfection in calcification as a fora- 
men for nerve VI is less certain. 

Ventrally, the orbital rim turns sharply outward to form a 
subocular shelf ; this is far narrower than the dorsal rim. An- 
teriorly, the ventral surface of the braincase has been badly 
eroded, and it is possible that in life this shelf may have been 
more developed than the specimen now suggests. 

Postorbital process. This process is highly developed. Its 
dorsal surface is convex in section, the anterior portion being 
a lateral continuation of the orbital roof. It curves markedly 
downward laterally. The anterior surface, conforming to the 
spherical contour of the orbit, is essentially a smooth wall, ver- 
tical below, curving outward above (Fig. 3A). From the ventral 
base of the anterior surface of the process a distinct groove, 
bounded below by the subocular .shelf, extends outward for some 
distance. This may have served as a channel for the mandibular 
ramus of the trigeminal nerve. Distally, the postorbital jirocess 
proper curves forward as well as downward. Back of this area 



opV+VII 





B 



Fig-. 3. A, iuitciior, and B, posterior views of tlie right postorbital proc- 
ess. Abbreviations as in Figure 1. X Va- 



ROMER: TAMIOBATIS BRAINCASE 95 

(Fig. ;JB) is a well-deiiiu'd arlicular surface, concave in cross 
section, for the palatoquadrate. Its curved anterudorsal bound- 
ary is the posterior border of the postorbital process i)roper, its 
ventrolateral boundary a ridge situated on a posterior accessory 
buttress of the postorbital process. Posteriorly, proximal to the 
articular area, the postorbital process is pierced diagonally by 
a prominent foi-amen. Its median opening enters the process 
well ventrally on the posterior surface; it emerges on the ante- 
rior surface just above a lateral extension of the subocular shelf. 
This foramen may have served for the passage forward of the 
pretrematic ramus of the facial nerve. At the base of the process 
a large foramen, surely carrying the vena capitis lateralis, 
pierces it in an anteroposterior direction. This leads from the 
ventral part of the orbital area, dorsolateral to the foramen for 
V2-V3, back to a ventrolateral shelf area in the otic region. 

Otic region. As noted above, the otic region is very long, as 
compared with that of modern elasmobranchs. Even excluding 
the occipital region from comparison, the length here is much 
in excess of the anterior portion of the braincase. It is broad 
as well as long (although the seeming relative breadth is un- 
doubtedly exaggerated because of dorsoventral crushing). For 
much of its length the median roof area is slightly concave in 
section — this a continuation of a slight median depression 
present in the interorbital region. Medially in the posterior half 
of the roof is an elongate fossa which obviously included the 
openings of the endolymphatic ducts. Posteriorly, this opening 
is surrounded by a low raised ridge ; for most of its length, 
however, it is bordered by a pair of prominent ridges, which 
may be termed the dorsal otic ridges. For the anterior two- 
thirds of their lengths these ridges have laterally a sharp curved 
border, somewhat concave in outline in dorsal view. This may 
have lain parallel to the ui)per inner margin of the palato- 
quadrate, with which it may have had a ligamentous connection. 
Posteriorly, the processes become narrow, and are mildly 
swollen on their dorsal surfaces. Distally, their terminations 
overhang somewhat flattened areas on either side of the posterior 
end of the endolymphatic fossa; the.se areas were presumably 
occupied by median dorsal segments of the axial musculature, 
and the tips of the processes may have been in continuity with 
some type of "nuchal" ligaments. As .shown by sections of 
pleuracanth braincases (similarly l)uilt in this region), the an- 
terior vertical canals of the internal ear lav beneath the anterior 



96 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

portions of the dorsal otic ridges, and part of the posterior ver- 
tical canals lay beneath the posterior portion of the ridges. 

Projecting laterally, the length of the otic segment, is a longi- 
tudinal ridge, rounded in section, which may be termed the 
lateral otic ridge. As shown by pleuracanth specimens, this 
lateral ridge contained the horizontal canal of the internal ear 
— a canal of remarkable length. Between dorsal and lateral 
otic ridges is a deep longitudinal holloAv, which may be termed 
the dorsolateral otic fossa. The posterior boundary of the fossa 
is a low rounded ridge which descends posterolaterally from the 
dorsal otic ridge ; this presumably overlies the posterior end of 
the posterior vertical canal. In the floor of the fossa is an oval 
area, broader posteriorly, in which no calcification of cartilage 
is present. I believe that this represents merely an absence of 
calcification in the surface cartilage in this region; it is im- 
probable that any opening was present here in life. No further 
openings are apparent in the boundaries of the dorsolateral otic 
fossa. It may have been partially occupied by axial musculature. 

Below the lateral otic ridge is a second longitudinal channel, 
which we may term the ventrolateral otic fossa. Its dorsal 
border is the lateral otic ridge ; its floor a lateral extension of 
the basicranial floor, which curves upward as well as outward. 
This upward curvature results in the formation of a longi- 
tudinal trough which extends m( st of the length of the fossa ; 
its outer margin is somewhat concave in contour as seen from 
above or below, although with a slight lateral projection (']>os- 
sibly post-mortem) at mid-length. Posteriorly this ti-ough, Avhich 
obviously carried the vena capitis lateralis, opens laterally some- 
what short of the end of the otic region. Above the level of the 
trough and just behind the postorbital process a well-developed 
foramen opens outward and backward. This is undoubtedly the 
opening for the facial nei've. An ojiening ])o.steroventi"al to this 
is perhaps for a middle cephalic vein. Farther posteriorly there 
are, on both sides of the specimen, two oval unealcified areas on 
the iinier wall of the fossa. T cannot interpret them as being to 
any degree functional; they are too far anterior for either to be 
reasonably interpreted as for nerve IX. 

Posteriorly, on either side, the otic region expands laterally 
into a prominent lateral otic process. The dorsal surface of the 
process is for the most part gently convex; its proximal part 
was presunuibly underlain l»y th(> posterior end of the horizontal 
semicircular canal. Close to its anterior end is a tiny dorsal 



RO.MKR: TA.MI015ATIS HIiAIXCASE 97 

foraiiK'ii which may have carried sonic coinponeiit — ?somatic 
— of tlie IX-X nerve complex. The distal end of the process 
and the distal ])art of its anterior margin terminate in thin 
blunt ridges which woiihl appeal- to have been articidar in 
nature, ])erhai)s having contact with some anterior meml)er or 
members of the gill arch series of cartilages. The anterodistal 
terminus of Ihe ])i'()ces.s is lilted prominently upward. 

A vei-y considci-abh' part of the anterior face of the lateral 
otic process is lacking in calcification; this area is (piilc ii-reguhir 
in outline, as may be seen in the figures. But no reason can be 
adduced for such a prominent lack of chondrification. It is 
improbable that the condition seen in the specimen was due to 
post-mortem loss of surface, for this region wa.s not exposed to 
weath(>ring of the nodule, and despite the irregularity of the 
"opening" here, closely similar patterns are ])resent on both 
sides. 

A.s noted below, the under side of the otic process is deeply 
undermined posteriorly. On either side, the calcified base of the 
otic process is se])arated from the basal plate of the I)raincase 
by a narrow slit in which no calcification is present. Whether 
this slit existed in life, and represents a persistent marker be- 
tween otic and occipital cartilages, or whether this is due to 
post-mortem crushing, is uncertain. 

Occipital region. This is relatively short, constricted in width 
posteriorly, and of lesser depth than the otic region. Dorsally, 
indications of division l)etwen otic and occipital regions are seen 
in the form of slight ridues which begin, on either side, lateral 
to the posterior end of the endolymphatic fossa and curve out- 
ward and backward to the posterior margin of tlie base of the 
otic processes. Certain of the markings here are apparently 
l)ost-mortem in nature, but probably represent, in any event, 
indications of structural weakness at the points of fusion of 
elements embryologically discrete. (Xo indications of separation 
of units are visible ventrally. ) 

Just posterior to a lov\- transverse ridge behind the endo- 
lymphatic fossa is a large triangular opening, facing dorsally. 
At first glance one would assume, from its position, that this is 
the foramen magnum. This, how'evei-. is not the case, but the 
nature of this opening is unknown. Possilily it merely repre- 
sents an uncalcified ai-ea in the braincase roof, but against this 
interpretation is the fact that the opening shows a distinct, if 
low, boundary ridge. Posterior to this o])ening there is a median 



98 BULLETIN : MUSEUM OF COMPAEATIVE ZOOLOGY 

occipital crest (incompletely preserved in the specimen). Below 
the posterior termination of this ridge lies the foramen magnum ; 
this is nearly completely obscured by dorsoventral crushing. 
The dorsal portion of the occipital segment is relatively narrow, 
its lateral boundaries curving medially and posteriorly from the 
posterior margin of the otic processes. This dorsal area, bound- 
ing laterall}^ the triangular dorsal opening, described above, 
and the occipital crest, is gently convex in vertical section ; 
there is present here a small foramen, perhaps for a "spino- 
occipital" somatic nerve ramus. 

Farther ventrally the occipital segment is much broader than 
it is dorsally, its lateral margins curving inward and then back- 
ward, from a point well out beneath the otic processes. The 
upper surface of this thin ventral region forms the floor of a 
cavity of considerable size which extends forward, contracting 
in width in its course, beneath the main expansion of the otic 
process and the dorsolateral margins of the occipital segment. 
This cavity was not explored to its full depth, but surely formed 
the exit for the vagus nerve and not improbably the glosso- 
pharyngeal as well. I believe I can make out, in the lateral wall 
of the cavity near its posterior end, the inner opening of the 
small foramen in the otic process, mentioned above, which may 
have carried a small somatic branch of the glossopharyngeal or 
vagus. 

The occipital condjde is, as preserved, much broader than 
high ; it is V-shaped in contour as seen from above or below, and 
deeply indented centrally, presumably for the notochord. 

Ventral surface. The ventral surface of the specimen was 
exposed when found and had been subject to weathering. The 
light-colored areas shown in the plate are regions in wdiich 
weathering had removed the thin surface calcification of the 
braincase floor; except anteriorly the damage was not severe. 
The ventral surface was essentially flat. In the interorbital 
region the lateral margins follow the curved line of the shelf 
underlying the orbit which, as noted earlier, has been destroyed 
in part by erosion. Behind the postorbital processes the floor 
broadens greatly, its lateral borders curving ujjward somewhat 
to form the margins of the trough which carried the vena capitis 
lateralis. Beyond the otic process there is a moderate constric- 
tion in width to the margins of the condyle. As suggested by 
the pattern of erosion, there were slight longitudinal ridges on 
either side of the midline toward the back; these merged 
anteriorly. 



ROMER: TA.MIOHATIS BKAINCASE 99 




pop 



Fig. 4. Ventral view of the braincase; the pituitary region is imperfectly 
preserved. Abbreviations as in Figure 1. X V2- 



Posteriorly the braincase extends to a j^reater depth tliaii in 
typical modern elasniobranchs, for the paired anterior con- 
tinuations of the dorsal aorta ("common carotids") entered 
the braincase floor a short distance anterior to the condyle. 
Well forward in the otic region a pair of openings presumably 
mark the exit of the carotids from the aortic canals, and, as may 
be seen from the plate, there is evidence of gi-ooves — presum- 
ably for internal carotids — leading from these foramina for- 
ward and medially toward the hypophysial region. Farther 
forward on each side is a foramen which may have been the 
point of entrance of the hyomandibular (pseudobranchial) 
artery. Still farther forward on either side is a further open- 
ing, from wliich a deep groove leads forward and outwai-d into 
the oi'bit ; presumably this was for an external carotid. 

It is unfortunate that almost the entire surface layer of 
calcified cartilage has been lost in the hypophysial region ; how- 
ever, it is reasonable to believe that the surface of the matrix 
essentially follows the surface contours. There was here a large 
oval depression, which may have contained an open hypophysial 
pit. Paired indentation.s leading forward from the front end 
of this depression suggest that the two internal carotids entered 
the braincase independently here. 



100 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

COMPARISONS 

As noted above, uncrushed Paleozoic elasmobraneh braincase 
material exists otherwise only in the case of the two late De- 
vonian specimens of "Cladodus" and the pleuracanth material 
from the Permian which I am currently studying. The Tamio- 
hatis type may be compared with these forms. 

The specimen studied by Stensio (1937) and named Cladodus 
hassiacus by Gross (1937) includes only the ventral half of the 
middle portion of the braincase. The roof is nowhere present ; 
the specimen ends anteriorly without including the front 
borders of the orbit and terminates posteriorly part way along 
the otic region. As far as preserved, the general proportions are 
comparable to those seen in Taniiobatis. The optic nerve, eye 
stalk, main trigeminal opening, and more dorsal opening for 
ophthalmic rami are present as in Tamiohatis, but the last two 
foramina are apparently less developed than in our type. Due 
to crusliing and erosion, I cannot tell whether or not Taniiohatis 
had a notch for palatoquadrate articulation {ohf in Stensio 's 
figure 1) or whether the ventral bloodvessel openings which he 
figures were present. Stensio has restored the nasal region di- 
rectly from Chlamydosdachus, but there is no specific reason for 
assuming that the pattern was of the fashion found in that 
modern genus. Of the postorbital process only the lower portion 
was present in his specimen, and, probably as a consecjuence, it 
appears to be slimmer than in Taniiohatis. Quite surely, had the 
process been better preserved, there would have been found, as 
in Taniiobatis and in Gross' specimen, an articular facet for 
the palatoquadrate, and not improbably a canal of the .sort which 
I have suggested as carrying the pretrematic ramus of the facial 
nerve (perhaps the notch which he illustrates at tlie tip of his 
postorbital process represents the remains of this canal). Stensio 
in his figure 3 shows, on the left side, two canals emerging poste- 
riorly from the base of the postorbital process, of which the upper 
is labelled as for the jugular vein, the lower for the main trunk 
of the facial nerve. The course indicated for the jugular is in an 
unusually high j^osition for that vein, and I suggest that witli 
better material it would be found that (as in Tainiohdtis) it is 
the ventral canal which carries the lateral head vein and tliat 
the dorsal opening is that for the facial nerve. 

As indicated by his figure 5 and the text, the canal region of 
the ear was incompletely preserved in Stensiii's si)ecimeii. Ap- 
parently parts, at least, of all tlir-ee canals were present in liis 



K()Mi;iv: TA.MlOliA'lIS lUvAIXCASE 101 

sj)(H*iim'ii. However, they apjx'cir to occupy a slioiM sjiace antoro- 
posteriorly — much shorter than is llic case in ph'uracanths, 
Tamiohatis, or (apparently) in Gross' spccinicn of "Cladodus/- 
This .seeniinji' abbreviation may well be due to ci-ushin<i' and im- 
perfections at the j)osterior end of Slensiii's spet'inien. 

In Stensio's, as in Gross' specimen, in Taniiobatis and in ])h'U- 
raeanths, and in contrast with Recent elasmobranchs, tlie "com- 
mon carotids" are carried well forward ventrally in the base 
of the braincase. A series of foramina farther forward in the 
braincase floor agree well in u'enei-al with those described by 
Gross and those present (in incomplete fashion) in Taniiobatis. 

Stensio's specimen is incomplete posteriorly; he arbitrarily 
terminates the braincase in his fig-ure 6 at a distance from the 
orbit comparable to that seen in modern elasmobranchs. Due to 
this arbitrary posterior termination, and to his restoration of 
the nasal region in accordance with that of Chlamydosclachus, 
the general picture of the braincase in his figure 6 is very similar 
to that of modern sharks. But quite surely better preservation 
of the specimen would have shown very different proportions, 
much more in keeping with Gross' Cladodus wildungensis, 
Tamiohatis and pleuracanths. In this instance, as in the further 
specimens to be discussed, certain features (the presence of an 
optic stalk, etc.) are closely comparable to those in modern 
elasmobranchs; others (as the canals for the "common caro- 
tids") are features probably of a primitive nature, lost or 
modified in modernized forms. 

The specimen studied by Gross (1937) and referred to 
Cladodus ivildungensis is from the same horizon and locality 
(Wildungen) as that of Stensio, and considered by him to be 
generically identical. It is much more complete. Anteriorly, it 
includes the posterior margins of the dorsal fontanelle, and thus 
lacks only a small area of presumed calcification in the uasal 
region; posteriorly much of the endolymphatic slit is present. 
and hence there has been lost only the short occipital region and 
the posterior end of the otic region (with the otic processes). 
The specimen is somewhat larger than Tamiohatis, but resembles 
that type closely in general proportions in both dorsal and 
ventral views, and has the great advantage of being uncrushed. 
Whereas, for example, this Cladodus specimen is but 20 per cent 
or so larger than Tamiohatis in dimensions measured on both 
upper and lower surfaces, its height at (for example) the level 
of the postorbital processes is approximately double that of 
the Tamiohatis type. 



102 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

As may be seen by comparing Gross' figure 1 with Figure 1 
of this paper, his braincase is in dorsal view very similar to 
that of Tamiohatis. Both show the notch for an anterior fonta- 
nelle, a broad interorbital region forming laterally a roof for 
the large orbit, and a row of nerve foramina for the supraorbital 
lateral line canal. In both there is a prominent postorbital 
process (somewhat imperfect dorsodistally in the Gross speci- 
men). In this specimen we find definite proof that — in contrast 
to Stensio's assumption — there was a greatly elongated otic 
region. As in Tamiohatis, there is a well-marked area of the 
dorsal ridges such as I believe were apposed to the palatoquad- 
rates. Centrally and posteriorly there is an elongate endolym- 
phatic opening like that of Tamiohatis. As in that form, a 
swelling (hB) posterolateral to that opening is obviously re- 
lated to the posterior vertical canal, thus showing that in 
"Cladodus," contrary to Stensio's interpretation of a much 
poorer specimen, the canal region was greatly elongate. Dor- 
sally, Gross' specimen becomes imperfect posteriorly before the 
end of the endolymphatic slit is reached. He tends to assume 
(presumably influenced by a comparison with modern sharks) 
that the terminus of the roof of the braincase had been nearly 
attained at this point. But comparison with Tamiohatis strongly 
suggests that a considerable area is absent here, including pro- 
jecting otic processes. It is unfortunate that it cannot be said 
whether the dorsal ridges terminated in the prominent pos- 
teriorly-projecting processes seen in Tamiohatis and pleura- 
canths. 

Ventrally, Gross' specimen again compares closely with 
Tamiohatis ; his figure 5 (except for the absent otic processes) 
compares closely with my Figure 4. 

The structure of the orbital region, seen in Gross' figures 3A 
and 3B, is comparable in most respects to Stensio's findings 
and those seen in Tamiohatis (Fig. 2). In all three there is a 
prominent oval for an eye stalk, an optic nerve foramen an- 
terior to it, and more dorsally, foramina for nerves III and IV. 
As in the case of Stensio's specimen, Gross was able to make 
out ventral foramina for an ophthalmic artery and pituitary 
vein — structures which crushing appears to have obliterated 
in Tamiohatis. In Tamiohatis there appears to be a single open- 
ing in the posterodorsal corner of the orbit for ophthalmic rami ; 
in C. wildnngensis there are two distinct openings here (0 Sup, 
Supf). I am unable to completely reconcile the foramina for 



KOMEH : TA.MIOHATIS HKAINCASE 103 

various elements of V and \'1I as determined by Gross with 
those wliich I appear to find in Tamiohatis or those identified 
by Stensio. As in Tamiohatis, but in disagreement Avith 
Stensio's description of his specimen, there is but a single an- 
teroposterior canal traversing the base of the postorbital process. 
As noted above, the postorbital process was incompletely pre- 
served in C. hossiacus; that in C. wildungensis agrees well with 
that of Ta)niohaiis in the presence of a canal for the pretrematic 
ramus of the facialis and a distinct articular area for the pala- 
tocjuadrate. 

In sum, apart from a few differences regarding nerve fora- 
mina, possibly due to imperfections in the materials, the brain- 
case described by Gross agrees in almost every preserved feature 
with Tamiohatis. It is obvious, assuming that Cladodus wildun- 
gensis and Cladodus hassiacus are really related, that the pro- 
portions attributed by Stensio to the braincase in his specimen 
are (literally) far short of the truth as regards its length. 

As noted earlier, I have long had in my possession consider- 
able materials of " Pleuracanthus" from the Lower Permian of 
Texas, and had, a number of years ago, begun a study of the 
braincase, including the serial sectioning of a number of speci- 
mens. I hope to complete this study in the not distant future, 
and will postpone any detailed comparison of this material with 
Tamiohatis and "Cladodus" until this has been done. It may 
be said in the meantime, however, that as far as can be seen at 
present, agreement is very close. If such a figure as that of the 
dorsal surface of the pleuraeanth skull published by me in 1933 
(fig. 26; 1945, fig. 55)1 j^g compared with that of Tamiohatis, 
it will be seen that the two are similar in all general regards 
(except for a somewhat greater lateral projection of the otic 
processes in Tamiohatis), and the same holds true for many 
other features of the anatomy. 

CONCLUSION 

I had at one time thought that, due to the great similarity 
between the pleuracanths and Tamiohatis, the latter might be 
an early representative of the pleuraeanth group. Against this 
is the fact that pleuracanths are mainly freshwater forms. 



iHussakofs flgures of this skull type (1911, pl. 29) are grossly inaccurate 
in a fashion similar to Eastman's misinterpretation of Tamiohatis. with dorsal 
and ventral surfaces reversed, the postorbital process identified iis nasal cap- 
sule, etc. 



104 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

whereas Tamiohatis is from a marine limestone. This is not a 
crucial argument, for the later plenracanths may well have 
migrated from salt water to fresh, and Tamiohatis might have 
been an ancestral marine form. But since tlie "Cladodus" 
specimens are, a.s far as known, in essential agreement with 
Tamiohatis and the plenracanths, it is more reasonable to be- 
lieve that we are here dealing with a truly primitive elasmo- 
branch type of braincase, characteristic of ancestral shark types 
in the Devonian, not improbably retained in more generalized 
Carboniferous forms, and persistently retained by the pleura- 
canth side-branch of the shark group. 

The most conspicuous difference between this type of primi- 
tive shark braincase and that of modern genera is, of course, 
the very long otic and occipital segments of the primitive 
braincase, with the more "expansive" development of the 
braincase cartilages to include the anterior part of the dorsal 
aorta within its substance. So radical are the differences in 
proportion here that it was not surprising that, in default of 
more complete material, Stensio restored his Cladodus specimen 
in abbreviate modern fasliion. I regard it as highly probable 
that all later elasmobranchs are descended from Triassic hybo- 
donts; in these forms shortening of the otic region had already 
occurred (cf. Hyhodas, as figured by Smith Woodward, 1916, 
fig. 3). It is to be hoped that further discoveries of Paleozoic 
sharks may at some future time give us knowledge of the phylo- 
genetic point at which this shortening occurred, and of the 
associated functional "reasons" (no doubt complex). It is of 
interest, in view of the belief of many that the elasmobranchs 
are allied to the placoderms, that in many members of that 
important Devonian group the "facial" region was, as in the 
older sharks, relatively short, and the otic plus occipital regions 
often greatly elongated. The change in proportions seen in the 
evolutionary history of the elasmobranch "skull" may well be 
merely one of a number of parallel developments in this regard 
in higher fishes and lower tetrapods. For example, the long- 
standing confusion as to the nomenclature of the dermal roofing 
elements of the frontal-parietal regions in rhipidistians was due 
to the fact that in the evolutionary series rhipidistians - am- 
phibians-reptiles there was a long-continued trend toward 
relative reduction of the otico-occipital region, wilh a coin'oini- 
tant rearrangement of the overlying dermal elements (Westoll. 
1938; see Homer, 1941, fig. 4). " 



ROMEK: TAMIOBATIS IJKAIXCASE 105 

One thus jiaiiis tlic impression tiial tiiere lias l)eeii, in tlie 
history of the giiatliostome fishes, a strony trend toward relative 
reduction of tlie posterior portion of tlie cranial structures and, 
very probably, a concomitant elaboration of the "facial" re- 
gion. Study of the functional chani>(»s whicli underlie tliis trend 
may be worthy of pursuit. 

REFEl?EX(i:S 

Eastman, C. R. 

1897. T(i))iiohatis vrtiisl ii.s ; ;i new form of fossil skate. Aiiier. Jour. 
Si-i., (4) 4: 85-90. 
Gross, W. 

1937. Das Kopf.skolott von Cladodun irildiuii/rn.si.s Jaekel. 1. Teil. 
Endocraniiini iiml Palnto(iua(lratuni. Seni'krnhergiana, 19: 
80-107. 
HUSSAKOF, L. 

1911. The Permian fislies of Nortli America. Carnegie Inst. Wash- 
ington, luilil. 146: 155-17.J. 
JiLLSON, W. R. 

1929. Geologic map of Kentucky. Kentucky Geological Survey, Frank- 
fort, Ky. 
ROMER, A. S. 

19oo. Vertebrate paleontology. Chicago, 491 pp. 2nd ed., 1945, 687 pp. 
1941. Notes on the crossopterygian hyomandibular and braincase. 
Jour. Morpli., 69: 141-160. 
Stensio, E. a. 

1937. Notes on tlie endocrnniuni of a Devonian Chidodus. Bull. Geol. 
Inst. Upsala, 27: 128-144. 

194."i. On the heads of certain arthrodires. Kungl. Svenska Vctensk. 
Handlingar, (3) 22 no. 1: 1-70. 
Westoll, T. S. 

1938. Ancestry of the tetra pods. Nature, 141 : 127-128. 
Woodward, A. S. 

1916. The fossil fishes of the English Wealden and Purbeck forma- 
tions. Palaeontographical Society, London, volume for 1915: 
1-48, pis. I-IX. 

(Received August 26, 1963) 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 






Plate 1. 

Dor.sal, lateral and ventral views of the type Inaim-ase of Tmniobatis 
vetustus, as preserved. The height has obviously been reduced by crushing. 
White areas on the ventral surface are those in which superficial calcification 
has been removed by erosion. X Vj. Drawn by N. Strekalovsky. 



Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. 131, No. 5 



THE TAXONOMIC STATUS OF HEPTAXODON AND 

DENTAL ONTOGENY IN ELAS3IODONTOMY8 AND 

AMBLYRHIZA (RODENTIA: CAVIOMORPHA) 

By 

Clayton E. Ray 

United States National Museum 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

May 25, 1964 



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WITH THE 

MUSEUM OF COMPARATIVE ZOOLOGY 
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Phylogeny and Evolution of Crnstacea. Proceedings of a confer- 
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Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 
Vol. 131, Xo. 5 



THE TAXONOMIC STATUS OF HEPTAXODON AND 

DENTAL ONTOGENY IN ELAS3I0D0NT0MYS AND 

AMBLYRHIZA (RODENTIA: CAVIOMORPHA) 

By 

Clayton E. Ray 

United States National Museum 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

May, 1964 



liull. Mus. Comp. Zool., Iliirvard I'liiv., 131(5): 107-127, May, 19(34. 

No. 5 — Tht Taxonomic Status of llcptaxodon and Dental 

Ontogeny i)i Elasniodontoiny.s and Aniblyrhiza 

[Rodcntia : Vaviomorpha) 

By 
Clayton E. Ray^ 

United States National Museum 

INTRODUCTION 

The affinities of the extinct Puerto Riean eavioinorph, Hep- 
taxodon hidens Anthony 1917, have been problematical owing to 
the supposed reduction of cheek teeth to two on either side above 
and below, with the first strongly dominant. This condition, 
grossly aberrant for a caviomorph, led some authors to isolate 
Heptaxodon in its own monotypic family (IMiller and Gidley, 
1918, p. 447, followed by Anthony, 1926,*^ p. 130) or subfamily 
(Anthony, 1917, p. 186 ;' 1918, p. 397). Others have included it 
in a subfamily (Simpson, 1945, p. 96, followed by Wood, 1955, 
p. 182) or family (Landry, 1957, p. 59) together with five^ 
other West Indian genera. If the stated diagnostic characters of 
Heptaxodon are accepted at face value, association at the familial 
level with any known genus of caviomorph seems indefensible. 
The down-grading in taxonomic isolation of Heptaxodon in the 
more recent works cited above undoubtedly reflects a growing 
disbelief in the reality of its apparent uniqueness, but it was 
H. G. Stehlin {in Stehlin and Schaub, 1951, p. 262, followed by 
Schaub, 1958, p. 736) who first interpreted the genus as a growth 
stage of Elasmodontomys ohJiquus Anthony 1916. This author 
arrived at the correct conclusion on the invalid premise that the 
dominant cheek teeth of Heptaxodon are P|-of Elasmodontomys . 
X-ray photographs of critical specimens, restudy of all denti- 
gerous elements of Heptaxodon, Elasmodontomys, and Amhly- 
rhiza in the collections of the American Museum of Natural His- 
tory (AMNH) and the Museum of Comparative Zoology (MCZ), 
and comparisons with developmental patterns in hystricomorphs 
and in other caviomorphs have shown, as pointed out in detail 
below, that the anterior cheek teeth of Heptaxodon are DP-|- 
of Elasmodontomys. This review of the evidence has made pos- 
sible a better understanding of dental ontogeny in Elasmodon- 
tomys and AmMyrhiza. 

1 This work was completed while the author was Assistant Curator in charge 
of fossil vertebrates at the Florida State Museum. Universitj- of Florida, Gaines- 
ville. 

- Six. if Quemisia, omitted by the al)ove authors, were included in the group, 
as it has been to the present by all authors who have discussed it. 



110 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

A word is necessary here regarding nomenclature of tooth 
components. Stirton (1935, p. 392) has derived from the tri- 
tubercular system a terminology for beaver teeth, and Fields 
(1957, p. 278) has extended it with additions to certain late 
Miocene dinomyids, pointing out that "the application of these 
terms does not necessarily imply homology but has been used 
as a matter of convenience." I have not felt justified in extend- 
ing to the highly evolved, hypsodont Elasmodontomys a system 
which ordinarily carries some connotation of homology. Further, 
the structure of the Elasmodoyitomys cheek tooth is so elegantly 
simple that it is most conveniently described in neutral geo- 
metric and numerical terms. 

Cope (1883, p. 5) has aptly characterized the units of which 
the cheek tooth of Amblyrhiza is composed as "columns of den- 
tine inclosed in ... a sheath of enamel," a description equally 
appropriate for Elasmodontomys. The columns and their 
sheaths are flattened anteroposteriorly and closely applied to one 
another, with a small amount of cementum interspersed. Suc- 
cessive columns are separated by transverse reentrants that pene- 
trate the full width of the tooth. Each reentrant may be desig- 
nated as outer or inner depending on whether its deepest proxi- 
mal extension is labial or lingual. Individual columns and re- 
entrants may be distinguished by numbering them serially from 
anterior to posterior in each tooth. The enamel of the anterior 
wall of each column (and thus the posterior wall of each reen- 
trant) is much thicker than that of the posterior wall (anterior 
wall of reentrant) in the upper teeth, and vice versa in the lower 
teeth. In both upper and lower teeth the free external enamel 
walls are invariably thick. Much confusion has arisen in de- 
scribing these teeth as a result of inconsistent reference to either 
columns or reentrants, and as a result of failure to detect the 
thin enamel walls, which appear only as hairlines on occlusal 
surfaces. The occlusal pattern of each column obliquely sec- 
tioned by wear takes the form of a much flattened ellipse. In 
some cases, even in long, little-worn teeth some reentrants are 
not completely penetrant but have their vertex tightly appressed 
to the adjacent external enamel wall so that it is visible far 
down the shaft of the tooth through the translucent external 
wall. In such cases, and in senescent teeth in which the enamel 
forms a single continuous trace on the occlusal surface, the 
pattern produced by each column is more appropriately desig- 
nated a loop. 



RAY : STATUS OF IIEPTAXODON 111 

D('V('l()})nioiit of tlie lower dentition of Elasmodontomijs will 
be treated first, followed by the less well documented upper den- 
tition of Elas)iio(]onfo))})js, and that in turn by the fragmentary 
data on Amhlyvliizn. Length of a given tooth is in all eases a 
maximum taken parallel to the longitudinal axis of the tooth, in- 
eluding roots where present. Selection of genera for comparison 
has been in part dictated by the availability of appropriate 
ontogenetic stages, and no a priori implication of relationship is 
intended. 

I wish to thank Professor Bryan Patterson, who initiated the 
present study, for generously turning over to me X-rays pre- 
pared by Dr. Rainer Zangerl of the Chicago Natural History 
Museum (CNHM) together with the drawings by Mrs. Dorothy 
Marsh that are reproduced in Figures 1 and 2. I wish to thank 
also the curators in the Department of Vertebrate Paleontology, 
American Museum of Natural History (AMNH), who permitted 
free use of the splendid collection of Antillean caviomorphs 
accumulated largely by H. E. Anthony; and the curatorial staffs 
of the mammal departments of the American Museum of Natural 
History, Chicago Natural History Museum, and Museum of Com- 
parative Zoology (MCZ) for making available modern compara- 
tive material. 

DENTAL ONTOGENY 

Lo\vER Dentition of Elasmoclontomys 

Certain critical specimens are described below in detail in 
order of increasing age, followed by a discussion of development 
and comparisons with other genera. AMNH 55030 and 55031, 
and MCZ 10132 have always been regarded as "Hcptaxodon," 
whereas AMNH 55037, in spite of its DP4, was identified quite 
correctly as Elasmodontomys. 

AMNH 55030. Left ramus with DP4 (Fig. lA). Figured by 
Anthony (1917, pi. 5, figs. 4, 6; 1918, fig. 38C, D, F; 1926, fig. 
48C, D, F). Mandibular symphysis open. Bone porous in tex- 
ture. DP4 with five columns, the first with a small, semi-isolated 
subsidiary pillar on its anterolingual wall, the pillar unworn, 
merging with the column at the alveolar border ; the fourth col- 
umn with a constriction in the middle of its occlusal surface. 
Occlusal area small ; obviously it would have increased with addi- 
tional wear. The X-ray photograph shows incipient double 
roots of DP4 (reflected externally by a bulge on the ventral 



112 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 




A \M 





B 





C 






D 



Figure 1. Early ontogeny of the lower dentition in Elasmodontomys 
obliquus, showing on the left (approximately X I'l) immature left man- 
dibular rami in lingual aspect, diagramniatieally represented largely on 
the basis of X-ray photographs, and on the right (approximatey X 2.2) 
the corresponding DP4 in occlusal aspect. In order of increasing age the 
specimens figured are: A, AMNH 55030; B, AMNH 55031; C, MCZ 10132; 
n, AMNH 55037. 



RAY: STATUS OF IIEPTAXODON 113 

border of the horizontal ramus), the crypt for Mi (the thin 
walls of which are bi-okeii throiifi'h in three places), and tlie base 
of the ineisive alveolus adjacent to the posterior bordei' of DP4. 
Leufith of DP4 approximately 1(5 mm. 

AMNII 55031. Left ramus with DP4 and Mj (Fig. IB). 
Sj'mphysis open. Bone porous. DP4 with five columns, the 
first two confluent anterolabially, the last two merf>ing lin<Tually 
2.6 mm proximal to occlusal surface. Occlusal surface near its 
maximum area. Mj apparently just at point of eruption; its 
columns open proximally. Incisive alveolus terminating adjacent 
to middle of M^. X-ray photograph shows DP4 with well 
formed double roots. Length of DP4 slightly less than 15.8 mm. 

MCZ 10132. Left ramus with DP4 and Mi (Fig. IC). Age 
apparently comparable to AMNH 55031. Symphysis open. Bone 
porous. DP4 with six columns, the first of which is subsidiary 
and confluent anterolabially with the second, with which it 
merges lingually 3.5 mm proximal to occlusal surface. Length 
of DP4 less than 17 mm. Discovery that DP4 was loose in its 
alveolus made possible direct confirmation of the interpreta- 
tion of the X-ray photographs which indicated well-formed 
double roots, and in addition revealed that the posterior root 
is subdivided transversely into two rootlets. Mj is just at the 
point of eruption but quite unworn, revealing minor subdivi- 
sions near the apices of its unworn columns which would have 
been expressed ephemerally at early stages of wear as isolated 
islands and as constrictions in the characteristic ellipses. There 
are four major columns Avith a fifth, anterior, minor one con- 
fluent anterolabially with the first major one. Incisive alveolus 
terminating adjacent to middle of Mj. 

AMNH 55037. Left ramus with DP4, M,, and Mo (Fig. ID). 
Symphysis open. DP4 deeply worn, with all five enamel columns 
confluent and the trace of the enamel a complex but continuous 
line on the occlusal surface. The occlusal area is much reduced. 
The tooth apparently has slipped partially out of its alveolus 
and subsequently become cemented in that position, revealing 
the bases of two strongly developed roots with the saddle be- 
tween them only 4.8 mm below the occlusal surface. Including 
the long roots, the tooth is no less than 13 mm long. A small 
hole inside the alveolus between the roots of DP4 opens into 
a large crypt for P4. No trace of P4 itself was detected. Mj 
is in full use, its enamel sheaths confluent at their exposed proxi- 
mal ends indicating termination of enamel growth ; no trace 
of root formation. Length of M^ is 32.1 mm. Longitudinal axis 



114 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

of Ml widely divergent from erypt of P4, directed posteroven- 
trad at angle of about 60° to occlusal surface, extending into 
angular process to the ventral border. M2 at point of eruption, 
unworn, consisting of four columns open at their bases, maxi- 
mum length 15.6 mm. Incisive alveolus terminating adjacent 
to posterior margin of Mj. 

AMNH 55041. Left ramus with M2 and alveoli of P4 and 
Ml. Symphysis tightly fused dorsally but open ventrally. P4 
alveolus very deep, producing prominent bulge on ventral bor- 
der of jaw. The alveolus has a small concavity on its anterior 
wall near the alveolar border, which may be the vestige of the 
alveolus of the anterior root of DP4, suggesting shedding of 
DP4 only slightly prior to the stage here represented. M2 is in 
full use, its columns confluent proximally indicating cessation 
of their growth. The tooth slopes posteroventrad so that its oc- 
clusal surface is highly oblique to its longitudinal axis. The 
base of the tooth lies posteroventral to the mandibular foramen. 
There is no external indication of Mj{, but there is sufficient 
space that the crypt and tooth primordium could be accommo- 
dated. The specimen has not been X-rayed. Incisive alveolus 
terminates adjacent to middle of Mo. 

AMNH 17137 h. Right ramus with P4-M3. Figured by Mil- 
ler (1929, pi. 4, fig. 1, la). P4-M2 in full use, whereas M3 is 
not erupted. Incisive alveolus terminating adjacent to middle 
of M2. 

The growing tip of the lower incisor of Elasmodontomys 
extends with increasing age progressively posterad, as far as 
the middle of M3 in the oldest observed jaw (AMNH 55039). 
A similar sequence occurs in Dinomys. In the youngest ob- 
served individual (AMNH 100011, M2 in initial wear) the tip 
lies at the posterior edge of M- ; in AMNH 100053 (Ms erupt- 
ing), at the posterior edge of M3 ; in AMNH 46551 (DP4 much 
worn), well behind M3. No such progression occurs in Dasy- 
procta; in individuals with only DP4 in use the growing tip of 
the incisor already extends posteriorly almost to the mandibular 
foramen. 

Anthony (1918, p. 399) considered that, "the [pre-] molar 
of Hcptaxodon is a logical development from a tooth like that 
of Elasmodontomys in which genus a tendency toward multi- 
plication of the laminae of the individual tooth has been noted, 
this increase in number of plates being accompanied by an ap- 
parent decrease in the number of the teeth." These differences 



RAY : STATUS OF IlEPTAXODON 115 

are here shown to be oiitoy,enetie rather than pliylogenetic. The 
differences in number of eolumns and in the related shape of 
occlusal surface between DP4 {" Heptoxodon") and P4 in 
Elasmodoniomys are analogous to those between the same two 
teeth in Dasyprocta, Cuniculiis, and Dinomys. The "Heptaxo- 
don molar" (DP4) has five (six in MCZ 10132) enamel loops 
on its triturating- surface as compared to four loops in P4 of 
ElasiiiodoHtoniys. In correlation with its greater numljer of 
enamel ellipses the occlusal surface of DP4 is anteroposteriorly 
elongate whereas in P4 of Elasmodontomys it is trigonal and 
more nearly equidimensional. DP4 of Dasyprocta has six trans- 
verse enamel units (each composed of two laminae of enamel 
with the intervening dentine) and is conspicuously elongate 
anteroposteriorly, whereas P4 has five transverse units and is 
subequidimensional. DP4 of Cuniculus has an anteroposteriorly 
elongate crown wuth at least four lingual reentrants, the most 
anterior of which is complex, whereas P4 has three simple lin- 
gual reentrants, and an equidimensional crown. In Dasyprocta 
and Cunicidus the enamel does not form well-defined ellipses on 
the triturating surface as it does in Elasmodontomys and in 
Dinomys. DP4 of Dinomys is composed of four discrete col- 
umns of enamel, as compared to three columns in P4 (an un- 
worn P4 in AMNH 46551 has a small cylindrical fourth column 
on its anterior face which merges proximally with the adjacent 
column). 

As might be expected, the number and configuration of the 
enamel ellipses or loops in DP4 of Elasmodontomys (and in 
Dasyprocta, Cuniculus, and Dinomys) varies individually and 
with degree of wear. In AMNH 55030 (Fig. lA) DP4 is in 
the initial stages of wear, as indicated by the small area of the 
wear surface and Ijy the division of the next to last enamel el- 
lipse into two ellipses. The tooth is peculiar in the presence of 
a subsidiary pillai- of enamel on its anterior face. The pillar 
is unworn but would be expressed on the wear surface by a 
small circle of enamel. With additional wear the area of the 
triturating surface would undoubtedly increase, the two ellipses 
unite, and the small pillar disappear, producing a crown pat- 
tern not unlike that of AMNII 55031. The condition of DP4 
in extreme wear is illustrated by AMNH 55037 in which the 
enamel no longer forms complete ellipses but forms one continu- 
ous trace on the wear surface. MCZ 10132 and AMNH 55031 
are of approximately the same age, judging by similar gross 



116 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

size, wear of DP4, development of Mj, and length of incisor 
alveolus. However, DP4 has six enamel loops in MCZ 10132 
and only five in the other three jaws. This additional loop can 
be ascribed to individual variation (perhaps as an expression 
of the same genetic tendency producing the small pillar in 
AMNH 55030) and undoubtedly would disappear with addi- 
tional wear. Stehlin and Schaub (1951) referred to the "Hep- 
taxodon molar" as a "frischer Pramolar," implying that the 
added enamel ellipses and elongate occlusal surface would be 
transformed by wear and (everlasting) growth into the con- 
figuration expected in P4 of Elas7nodo7itomys. That no such 
trend occurs is well shown by Figure ID, demonstrating con- 
clusively that the tooth in question is long-rooted and very 
nearly worn out before Mo is erupted. The double-rooted, mod- 
erately hypsodont first molariform tooth in each jaw shown in 
Figure 1 is quite in contrast to the single-rooted extremely hyp- 
sodont permanent molariform teeth of Elasmodontomys (such 
as Ml in Fig. ID), indicating that the first tooth is deciduous. 
The permanent molariform teeth of Elasmodontomys differ 
from those of Dinomys in that they are not evergrowing, a fact 
which was recognized by Anthony (1918, p. 383). Anthony, 
nevertheless, considered the molariform teeth of Elasmodontomys 
to be rootless, although he accurately described and illustrated 
the deposition of cement beyond the base of the enameled por- 
tion of the teeth. To me this deposition seems to be acceptable 
as root formation. In none of the isolated teeth available is the 
root entirely closed, but none of these teeth is in an advanced 
stage of wear. In a fragmentary left ramus (AMNH "4") the 
root of a deeply worn Mj is visible and broken in transverse 
section. The root is quite solid with the exception of a fine cen- 
tral canal. In the oldest availal)le ramus (AMNH 55039), P4. 
Ml, and M2 are worn almost to the base of the enamel with long 
roots broadly exposed. M3 is absent, but its well-preserved, 
conical alveolus tapers to a sharp apex clearly indicative of a 
closed root. The order of termination of enamel growth (and 
presumably also of root growth) of the molariform teeth is DP4, 
Ml, M2, P4, M3. That DP4 terminates its growth first is self- 
evident and as expected. In AMNH 55037 (Fig. ID), Mj has 
terminated its enamel growth prior to the formation of P4 and 
during the early growth of Mo. The conclusion that growth of 
M2 terminates before that of P4 is based on the advanced growth 
of Mo in AMNH 55037, in which P4 remains to be formed. The 



RAY : STATUS OF IIEPTAXODON 117 

bases of all four molarifonn teeth are exposed in AMNII 55044 
revealing- that P4, Mj, and M^ have "well-fornied open roots 
whereas M3 has terminated its enamel growth but formed no 
root. The termination of enamel growth in a given tooth seems 
to coincide with the initial wear of that tooth. This coincidence 
has been observed for DP4 (AMNII 550;:!0, Fi-'. lA), Mi 
(AIMXII 550.S7, Fig. ID), and M3 (AMNH 55044). The a])- 
propriate stages for the demonstration of this feature in P4 
and Mo are not available. 

In Elasmodoniomya, P4 comes into use prior to M3, as shown 
by AMNH 17 1)37 j in which P4 is considerably worn and M3 is 
unerupted. Anthony apparently considered this to be the es- 
tablished sequence in all hystricomorphs (including caviomorphs) 
for he concluded that the functional tooth in "Hepto.rodon" 
was a fourth premolar on the basis of "the great importance 
in the hystricomorph tooth row assumed by the last premolar, 
since it always becomes functional before the last molar. . . ." 
(1918, p. 398). However, M3 (and M^) l^ecomes functional prior 
to P4 (and ?■*) in Hysfrix, Athcrurus, Ercthizon, Binomys, 
Olenopsis (Fields, 1957, p. 327), Dasyprocta, and Cuniculus,^ 
and the P-|- are entirely suppressed in modern echimyids and 
capromyids and thus of course do not precede the M.^ (Wood 
and Patterson, 1959, p. 301). 

The overall sequence of eruption in Elasmodontomys is DP4, 
Mj, M2, P4, M3, identical to the sequence of termination of 
enamel growth, as might be expected. DP4 is shed after the 
eruption of Mo. as .shown by AMNH 55037 (Fig. ID), and 
(obviously) prior to the eruption of P4 (or technically shortly 
afterwards, for DP4 may have remained functional after P4 
had thrust up between its roots, above the alveolar border, as 
noted below in Dinomys) . 

Tooth formation in Elasmodontomys apparently was very 
rapid. In AMNH 55030, for example, there is no trace of Mi 
other than its crypt, whereas in AMNH 55031 and MCZ 10132 
Ml is well formed and on the point of eruption. The amount 
of wear incurred by DP4 during this interval is only moderate. 



2Iii(livicliials of appropriate ago wero fower than desirable for i\\\ forms iiicn- 
tioned, but only in borderline cases would variation be expected to be so jri-ent as 
to affect sequence. One such borderline case was noted in caviids in which a 
specimen of Microcavia australis (MCZ 18995) was observed with DI'^ and 
m|^ in use, whereas a specimen of Caria porccUiis (MCZ 942()) and one of C. 
tschudii (MCZ 177:^6) have p| in full use and Mf barely breached by initial 
wear. 



118 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

Similarly, DP4 in AMNH 55037 is worn almost to the base of 
its enamel, but P4 remains unformed although its crypt is pres- 
ent. In a specimen of Dinomys (AMNH 46551) the left DP4 
has been broken off revealing a large P4, the crown of which 
stands well above the alveolar border. The right DP4 of the 
same individual is in place and much less worn than the same 
tooth in AMNH 55037. 

The straight -line distance between the tip of the angular proc- 
ess and the anterior extremity of the jaw in MCZ 10132 (the 
only "Heptaxodon" jaw on which any sort of length measure- 
ment could be taken) is 54.5 mm, or about 60 per cent of the 
similar measurement in an adult jaw of Elasmodontomys (90.0 
mm in AMNH "4"). In Dasyprocta the corresponding figures 
are 36.9 mm in MCZ 28091 (developmental stage comparable to 
MCZ 10132) and 60.0 mm for MCZ 32012, a young adult, again 
giving a percentage slightly greater than 60. Undoubtedly the 
precise correlation between these growth stages in Dasyprocta 
and Elasmodontomys is fortuitous, but it does indicate that the 
increase in gross size demanded of "Heptaxodon" in order for 
it to develop into Elasmodontomys is not unreasonable. 

Upper Dentition of Elasmodontomys 

Anthony concluded that AMNH 17101 should represent the 
type of a new genus with remarkably reduced dentition on the 
basis of the following premises : 

1. The type palate "bears all the appearance of maturity" 
(1918, p. 398). 

2. "The second and last tooth . . . appears to be an unworn 
tooth, not yet above the gum, but . . . may well be regarded as 
having dropped deeper into the alveolus than the normal posi- 
tion" (1917, p. 184). 

3. "It is apparent from the fragment [of the palate] that 
there is room for no more than the two teeth" (1917, p. 184). 

If the first observation is correct then the third furnishes 
valid evidence for the conclusion that the molariform teeth are 
reduced to two in each series, but if the palate (and the lower 
jaws) is that of a juvenile individual, it would not be expected 
to accommodate the full adult dentition. Anthony apparently 
did not consider the possibility that the palate (and the lower 
jaws) might be young enough for the functional tooth in each 
series to be a deciduous premolar. Although the bone of the 
I)alate is rather dense in texture, the fact that M^ is little 
developed (maximum possible length 10.9 mm compared to 



RAY : STATUS OP HEPTAXODON 119 

25-30 mm for M^ with crown complete, but lacking root) and 
unerupted, and that the palatal sutures are open, clearly indi- 
cates that the specimen is immature. There is no indication 
that Ml has "dropped deeper into the alveolus than the normal 
position." Assuredly it was not yet a functioning tooth, hut 
was on the verge of eruption. Tlie developmental stage of 
AMNII 17101, the type palate, approximates most closely that 
of MCZ 10132 among the lower jaws. 

An ontogenetic sequence similar to that proposed here from 
"Heptaxodon" to Elasmodo^itomys occurs in Dasyprocta. Sev- 
eral young individuals of Dasyprocta (MCZ 28091, 34962, 
34963) were observed to have in use only the well-worn decidu- 
ous fourth premolars with the first molars just at the point of 
eruption. This condition is comparable to that in AMNII 55031 
(Fig. IB) and MCZ 10132 (Pig. IC). Obviously there is a con- 
siderable period in the early growth of Dasyprocta during which 
the deciduous fourth premolars constitute the entire cheek 
tooth battery, as in "Hcptaxodon." In spite of this, the adults 
have the more orthodox formula of one premolar and three 
molars in each series, as in Elasmodontomys. DP^ of Elasmo- 
dontomys is composed of seven columns of enamel, the first two 
of which merge labially less than one mm proximal to the oc- 
clusal surface, and the last two of which are confluent lingually 
at the occlusal plane and merge labially as well about two mm 
proximal to it. Just as in the lower dentition, DP* in Dasy- 
procta, Cuniculus, Dinomys, and Elasmodontomys has a longer 
occlusal surface made up of more units than does P*. In the 
upper dentition of Elasmodontomys, both DP* (with seven) 
and P* (with five) have more enamel columns than their in- 
ferior counterparts (DP4 with five or six, P4 with four). 

T^nfortunately, documentation for dental succession is less 
satisfactory for the upper dentition than for the lower. How- 
ever, it is clear from AMNH 17101 that DP* only is in use for 
a considerable period in early ontogeny, and that it is followed 
in eruption by ]\P. The next stage represented is that of AMNH 
17132 with P*-M2 in use on either side and without trace of M-'^ 
or space for its development. Anthony (1926, pp. 108-109) 
tentatively interpreted this specimen as an example of evolution 
by discontinuous variation, supposing that the molars were re- 
duced to two, and that the occlusal length of P*-M2 was in- 
creased to compensate the suppression of M-^. In fact, the oc- 
clusal length of each molar is near its maximum at the onto- 
genetic stage here represented, as the shaft of each molar is 



120 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

directed strongly posterodorsad so that the occlusal surface 
intersects it at a highly oblique angle. In addition, the enamel 
columns of all cheek teeth in this specimen have undergone post- 
mortem separation, which has exaggerated their apparent occlu- 
sal length. Anthony felt that eruption of M-| in Elasmodon- 
tomys was unusually late in ontogeny for a " hystricomorph, " 
indicating a tendency toward suppression. He contrasts the 
condition with that in Hydrochoerus and Capromys, unfortu- 
nately each representative of a group highly precocious in den- 
tal ontogeny. AMNH 17132 is here regarded as a normal stage 
in the ontogeny of Elasmodontomys, indicating that P* pre- 
cedes M^ in development. AMNH 55047 is only slightly more 
advanced than 17132, having P^ well worn and M^ in an 
early formative stage, A specimen of Cimiculus (MCZ 31823) 
represents a similar developmental stage, having DP^-M|- 
in use, wdth M|^ newly erupted and little worn, and tiny (each 
less than 2 mm in diameter), superficial crypts for M-^ present 
behind M|-. No doubt this individual would have attained the 
full adult dentition, had it survived.^ Definite evidence on 
tooth sequence in the upper dentition of Elasmodontomys is 
lacking only for the relation between M- and P'*. With only 
this point unsupported by specimens, the sequence may be given 
as DP4, Ml, M2, P4, M3. 

The peculiar spatial relationships among the developing up- 
per incisor, DP'*, and P* require special attention. In the type 
specimen of "Hcptaxodon hidens" (AMNH 17101) the incisive 
alveoli, partially filled with matrix, terminate directly above 
DP*. In specimens of Elasmodontomys with P-* in use, the 
growing tip of the incisor intrudes between the shafts of P'* 
and Ml. The shafts of the molars lie parallel to one another 
and are directed posterodorsad from the occlusal surface, 
whereas the shaft of P* extends anterodorsad from the occlu- 
sal surface. In old individuals (e.g. AMNH 17129) the alveo- 
lus of P* comes to lie shallowly under the surface of the ros- 
trum, below the incisive alveolus. Unfortunately, growth stages 
between the juvenile AMNH 17101 and specimens with P^* 
already functioning are not represented. These stages should 
be interesting developmentally as it is impossible to suppose 
that sufficient space could exist between the roots of DP"* and 
the base of the incisor for the formation of the hypsodont P'*. 



sSchreuder (193.3, p. 252) hits also questioned Anthony's interpretation of 
AMNH 17132 and compared it to immature Cunicuhis. 



RAY : STATUS OF HEPTAXODON 121 

I would expect to find the crypt for the developing P-* antero- 
dorsal to DP*, not directly dorsal to it. X-rays of AMNH 
17101 have not been altogether satisfactory owing to the super- 
position of images from right and left sides of the specimen, 
but small crypts are indeed present in the expected position 
just anterior to the infraorbital foramen and adjacent to the 
premaxillary suture. No suggestion of a cavity is present im- 
mediately dorsal to the base of DP'*. 

Lower Dentition of Amhlyrhiza 

Evidence on sequence of eruption in Artiblyrhiza is limited 
to a single fragmentary left mandibular ramus in matrix 
(AMNII 55036). The cheek teeth are represented by vestiges 
of DP4, a fully-formed but unerupted P4, and fragmentary 
Ml and M2. P4 extends proximally at least to the ventral mar- 
gin (external curve) of the incisive alveolus, a minimum length 
of 21 mm. The distal extremity of the tooth has been broken 
off level with the alveolar border, but clearly very near its tip. 
The three separate enamel columns are of reduced size on their 
broken ends, and the middle column is subdivided, with a circu- 
lar island at the labial extremity of its broken end — both fea- 
tures indicative of a fresh, unworn tooth. Immediately anterior 
to the alveolus of P4 is a small, matrix-filled circular excavation 
about 3.4 mm in diameter, and immediately posterolingual is 
a shallow elongate one about 3.3 mm in anteroposterior diameter, 
and 1.8 mm in transverse diameter. These are undoubtedly the 
alveolar sockets for the roots of a deeply worn DP4, which may 
have been lost after death or shed shortly prior to death. A 
specimen of Chinchilla (MCZ 7276) has a shallow pit anterior 
to and confluent with the alveolus of P4 on either side of the 
mandible. A specimen of Cuniculus (MCZ 31752) has DP4 in 
use on both sides, but in a very advanced state of wear, with 
much basal resorption. Eight DP4 is kept in place mainly by 
its anterior root, the posterior ones having been largely re- 
sorbed. The distal tip of P4 extends above the alveolar border 
beneath the deeply w'orn DP4. In another specimen of Cunic- 
ulus (MCZ 32078) P4 is in use, but immediately anterior to it 
on either side is a shallow^ transversely elongate depression 
which on the left side retains a small peg of DP4. These speci- 
mens are, respectively, slightly younger than and slightly older 
than the jaw of Amhlyrhiza in relative age. 



122 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

The molars in AMNH 55036 are highly fragmentary. The 
remnant of Mi does extend high above its alveolar border, and 
must have been functional. M2 is broken away at the alveolar 
border, but its base is fully exposed (though broken) revealing 
that enamel growth was complete. The preserved portion of the 
tooth is 38.8 mm long and extends to the ventral border of the 
jaw. M2 must have erupted, as indicated by its advanced de- 
velopment and unconstricted alveolar border. Its developmen- 
tal stage lies between that of AMNH 55037 (Fig. ID) and 
AMNH 55041 in Elasmodo7itomys. It is probable that the se- 
quence of eruption was DP4, Mi, M2, P4, and Mo in AmUyr- 
liiza, just as in Elasmodontomys. 

As in Elasmodontomys, the shafts of tlie molars are directed 
posteroventrad, diverging proximally from the more nearly ven- 
trally directed .shaft of P4. In older jaws of Amhlyrhiza, the 
incisive alveolus extends well beyond the posterior margin of 
M3. 

Upper Dentition of AmMyrhiza 

The only specimen significant for the ontogeny of the upper 
dentition is an isolated right DP^, AMNH 55035 (Fig. 2). The 
tooth is regarded as deciduous on the basis of its small size 
(maximum length 19.8 mm), completed enamel deposition, and 
anteroposteriorly elongate occlusal surface composed of five units 
rather than four (upper) or three (lower) as in P^. It is 
identified as DP"^ rather than DP4 on the basis of the curvature 
of its .shaft. 

At the wear stage represented, the occlusal surface is charac- 
terized by five flattened ellipses of enamel. The first three are 
distinct from one another and from the fourth, but the fourth 
is broadly confluent witli the fifth, a subcircular loop set off 
from the fourth only by shallow lingual and labial reentrants. 
The foui'th and fifth columns would have merged with much less 
than one millimeter of additional wear. The labial reentrants 
separating columns are all quite shallow, extending proximally 
a maximum of 2.5 mm in the first, and decreasing successively 
to almost nothing in the fourth. The lingual reentrants display 
a more radical decrease posteriorward in proximal extent, from 
11.6 mm in the first, to 5.9 in the second, to 0.6 in the third, 
and practically nothing in the fourth. The tooth must have 
belonged to a very young animal, as its occlusal surface had 



RAY : STATUS OF HEPTAXODON 



123 







D 



Figure 2. Isolated right DP4 of Amblyrhiza inundafa (AMNH 55035) 
in labial (A), lingual (B), occlusal (C), and proximal (Z>) aspects. An- 
terior is to the right in (A) and (C), to the left in (B) and (D). X 3. 



yet to attain its greatest area. Breakage at the base makes it 
impossible to determine the status of root formation. 

It may be noted here in passing that the relationship of the 
upper incisor to the cheek tooth row in Amhlyrhiza is grossly 
different from that described above in Elasmodontomys. As 
Schreuder (1933, p. 243) has pointed out, the rostrum of Am- 
hlyrhiza is greatly elongated, with the upper incisor terminat- 
ing far in advance of P*, not between P^* and M^. I do not 



124 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

feel, however, that the similarity between Amblyrhiza and Chin- 
chilla in this feature is indicative of relationship, for Elasmo- 
dontomys and Lagostomus have short rostra with the base of 
the incisive alveolus overlapping and closely approaching P*, 
respectively. 

Summary of Dental Ontogeny 

"H(ptaxodon" represents a protracted early stage in the 
ontogeny of Elasmodontomys, in which the DP^ constitute the 
sole or at least dominant functional elements in the cheek 
tooth series. The elongate occlusal surface wdtli increased num- 
ber of laminae in the DP^ presumably is correlated "vvith this 
long period of use. The sequence of eruption, growth cessation, 
and root formation in Elasmodontomys, and in Aniblyrhiza as 
far as the meager data show, is DP|, M|, Mf , P-|, M|. 

The growing tip of the lower incisor extends progressively 
farther posteriorly with increasing age in Elasmodontomys. 
The condition in Amtlyrhiza is unknown. The growing tip of 
the upper incisor in Elasmodontomys lies directly dorsal to DP 4, 
leaving insufficient space for the development of P^ in that 
position. P4 develops anterodorsal to the roots of DP-* and 
anteroventral to the proximal end of the upper incisor. The 
growing tip of the upper incisor in Amhlyrhiza. lies in the 
greatly lengthened rostrum, far anterior to the cheek teeth. 
With the possible exception of the anteriorly displaced P* 
locus, every feature in the dental ontogeny of Elasmodontomys 
has been observed in other (non-heptaxodontid) caviomorphs 
as well. 

DISCUSSION 

The West Indian genera Heptaxodon, Elasmodontomys, Am- 
blyrhiza, Clidomys, Speoxenns, Spirodontomys, and (when it 
has been considered) Quemisia, have been associated in a single 
subfamily. Quemisia will be discussed elsewhere. '' Heptaxo- 
don" is based on juvenile specimens of Elasmodontomys, and 
is a junior synonym of the latter. I am as yet unprepared to 
make pronouncements on the poorly known Jamaican forms, 
Clielomys, Speoxenns, and Spirodontomys, and thus by default 
prefer to leave them, at least temporarily, in association with 
the present group. There is little positive evidence to support 
the association, but neither is there justification for placing 



RAY: STATUS OF 1 1 KI'TAXODOX 125 

them elsowhero in tlie present state of onr kn<)\vled<2:e. Elasmo- 
dontomys and Amhlyrhiza assuredly are closely related, and 
fully warrant association at the subfamilial level. This sub- 
family is best reo:ar(led as a member of the family Dinomyidae, 
in an arrantrement similar to that proposed by Schanb {in 
Stehlin and Sehaub, 1951, p. 370), or possibly as a member of 
a family very close to the Dinomyidae (Wood, 1955, p. 182). 

FAMILY-GROUP NOMENCLATURE 

Anthony (1917, p. 186) proposed three monotypic subfami- 
lies of Chinchillidae, the Amblyrhizinae, Elasmodontomyinae, 
and Heptaxodontinae, on successive lines of text in that order. 
Simpson (1945, p. 96) synonymized the three. Althouo'h Simp- 
son neglected to mention Aml)lyrhizinae explicitly, his inten- 
tion is clear in that he included Amhlyrhiza in the single re- 
sultant subfamily, for which he selected the name Heptaxodon- 
tinae, a choice undoubtedly dictated by his utilization of the 
name Heptaxodontidae, first considered as a full family by 
Miller and Gidley (1918, p. 447). If subfamilial names are re- 
garded as not influencing priority among full familial names, 
then Heptaxodontidae is the only valid choice. However, under 
the present International Code of Zoological Nomenclature 
(1961, Art. 23), all family-group names are regarded as coor- 
dinate for purposes of priority. In the present case, this con- 
troversial rule would have made possible the selection of a more 
satisfactory family name, either Amblyrhizidae or Elasmodon- 
tomyidae, both names based on older, better known genera, and 
as subfamilies both having line priority over the name Heptaxo- 
dontinae. Even so, Simpson, in the capacity of first reviser 
(International Code, 1961, Art. 24), has determined the relative 
priority among these simultaneously published names by select- 
ing Heptaxodontinae as the senior synonym, and Amblyrhizinae 
and Elasmodontomyinae as the junior synonyms. Thus, Hep- 
taxodontidae remains the valid name whichever system of pri- 
ority is invoked. This situation is, unfortunately, not altered 
by the fact that Heptaxodon hidens Anthony 1917 is a junior 
synonym of Elasmodontomys ohliquns Anthony 1916. The Inter- 
national Code (1961, Art. 40) states explicitly, ''w^hen ... a 
nominal type-genus is rejected as a junior synonym, a family- 
group name based on it is not to be changed ..." Thus, 
although there has been heated debate and strenuous disagree- 
ment on this subject, the rules are clear and ought to be followed. 



126 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

The family-group name Heptaxodontinae remains available, 
and is not to be replaced by the name Amblyrhizinae An- 
thony 1917 as Schaub {in Stehlin and Schanb, 1951, pp. 96, 
370; and 1958, p. 736) has proposed. 

LITERATURE CITED 

Anthony, H. E. 

1917. New fossil rodents from Porto Rico, with additional notes on 
Elasviodontomys obUquus Anthony and Meteropsomys insulans 
Anthony. Bull. Amer. Mus. Xat. Hist., vol. 37, pp. 183-189. 

1918. The indigenous land mammals of Porto Rico, living and ex- 
tinct. Mem. Amer. Mus. Nat. Hist., n.s., vol. 2, pt. II, pp. 
329-435. 

1926. Mammals of Porto Rico, living and extinct — Rodentia and 
Edentata. New York Acad. Sei., vol. 9, pt. 2, pp. 97-241. 

Cope, E. D. 

1883. On the contents of a bone cave in the island of Anguilla (West 
Indies). Smithson. Contr. to Knowl., vol. 25, art. 3, pp. i-iv 
and 1-30. 

Fields, R. W. 

1957. Hystricomorph rodents from the late Miocene of Colombia, 
South America. Univ. Calif. Publ. Geol. Sci., vol. 32, no. 5, 
pp. 273-404. 

International Code of Zoological Nomenclature. Adopted by the XV In- 
ternational Congress of Zoology (Ed. N. R. Stoll, Chairman, 
et al.). 1961, Internatl. Trust for Zool. Nomencl., London, 
xvii + 176 pp. 

Landry, S. O., Jr. 

1957. The interrelationships of the New and Old World hystrico- 
morph rodents. Univ. Calif. Publ. Zool., vol. 56, no. 1, pp. 1-118. 

Miller, G. S., Jr. 

1929. A second collection of mammals from caves near St. Michel, 
Haiti. Smithson. Misc. Coll., vol. 81, no. 9, pp. 1-30. 
Miller, G. S., Jr. and J. W. Gidley 

1918. Synopsis of the supergeneric groups of rodents. Jour. Wash- 
ington Acad. Sci., vol. 8, no. 13, pp. 431-448. 
Schaub, S. 

1958. Simplicidentata (=:Rodentia). Pp. 659-818, in J. Piveteau 
(Ed.), Traite Paleont., t. VI, vol. 2, pp. 1-962. 

SCHREUDER, A. 

1933. Skull remains of Amblyrhiza from St. ^Martin. Tijdschr. 
Nederl. Dierkundige Vereeniging, ser. 3, vol. Ill, pt. 4, pp. 
242-266. 
Simpson, G. G. 

1945. The principles of classification and a classification of mam- 
mals. Bull. Amer. Mus. Nat. Hist., vol. 85, pp. I-XVI, 1-350. 



BAY : STATUS OF IIEPTAXODON 127 

Stehlin, II. G. and S. Schaub 

1951. Die Trigonodontie der simplieidentaten Nager. Schweiz. Naturf. 
Ges., Paliiont. Abh., vol. 67, pp. 1-385. 
Stibton", R. a. 

1935. A review of the Tertiary beavers. Univ. Calif. Publ., Bull. 
Dept. Geol. Sci., vol. 23, no. 13, pp. 391-458. 
Wood, A. E. 

1955. A revised classification of the rodents. Jour. Mammalogy, vol. 
36, no. 2, pp. 165-187. 
Wood, A. E. and B. Patterson 

1959. The rodents of the Deseadan Oligocene of Patagonia and the 
beginnings of South American rodent evolution. Bull. Mus. 
Comp. Zool., vol. 120, no. 3, pp. 279-428. 

(Received December 1962.) 



Bulletin of the Museum of Comparative Zoology 

II A R V A R D UNIVERSITY 

Vol. 131. No. 



THE SKELETON OF THE LOWEU (AKliOXl KEKOTS 
LABYKIXTIIODOXT I'lfOLIDOGASTER PISCIFOmils 

Bv Alfred Siiiii.'wooi) 1\()mi':r 



With One Plate 



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Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 
Vol. 131, No. 6 



THE SKELETON OF THE LOWER CARBONIFEROUS 
LABYRINTHODONT PIIOLIDOG ASTER PISCIFORMIS 

By Alfred Shekwood Romer 



With One Plate 



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Bull. Mus. Comp. Zool., Harvard Univ., 131(6): 129-159, May, 1964. 

No. 6 — The Skeleton of the Lower Carhoniferous 
Lahyrinthodont Pholidojjaster pisciformis 

By Alfred Sherwood Romer 

INTRODUCTION 

Altlioii<i'Ii llie ancient lahyrinthodont amphibians are of over- 
M'liehnin<>' importance in the story of tetrapod evolution, our 
knowledge of their early evolution and radiation is still exceed- 
ingly fragmentary. On the one hand, we are fortunate in 
having materials (as yet not fully described) from the late 
Devonian of East Greenland (Save-Soderbergh, 1932; Jarvik, 
1952, 1955) which illustrate a very early phase of amphibian 
history ; on the other, we have a very considerable knowledge of 
Permian and Triassie labyrinthodonts. But most of the crucial 
stages in lahyrinthodont evolution obviously occurred during 
the Carboniferous, and here our knowledge is distressingly in- 
complete. A fair amount of material is known from the later 
Carboniferous — the Pennsylvanian — but is as yet far from 
adequately described. Poorer still is the situation as regards 
the earlier — Mississippian — stage of the Carboniferous. A 
very limited amount of North American material of this age 
from West Virginia is now known and under description by 
Hotton and the writer. Otherwise, as reviewed by Watson 
(1929; cf. Panchen and Walker, 1960, pp. 327-328), Lower 
Carboniferous labyrinthodonts are known only from a very few 
specimens from Scotland, and these are mainly of a fragmentary 
nature. 

In consequence, the type of Pholidogaster pisciformis Huxley 
is of unique importance as the only articulated skeleton of a 
Lower Carboniferous lahyrinthodont described up to the pres- 
ent time. As noted by Huxley (1862), the specimen, discovered 
in the Gilmerton Ironstone of the Edinburgh coalfield over a 
century ago, was originally acquired by Sir Philip Bgerton and 
the Earl of Enniskillen, "but as, on mature consideration, it 
appeared to them not to be a fish, it w^as handed over to the 
British Museum." Huxley described it briefly. Watson, in his 
1929 review of Carboniferous labyrinthodonts, gave an account 
of such anatomical features as could then be made out. Re- 
cently Mr. A. E. Rixon has further prepared the specimen, re- 
vealing a considerable amount of new anatomical data, particu- 
larly as regards the trunk vertebrae, thus rendering further 
description advisable. 



132 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

I wish to thank Keeper Errol I. White for the privilege of 
stud^'ing this important specimeii. I am grateful for the 
friendly and helpful reception given me at the British Museum 
during the course of this work, not only by Dr. White but by 
other members of the staff, particularly Dr. W. E. Swinton and 
Mr. Barney Newman. And I am, of course, particularly in- 
debted to Mr. Eixon for undertaking the preparation of this 
difficult material. 

The specimen comes from the Gilmerton Ironstone of Gil- 
merton, in the Midlothian Coalfield of the Edinburgh region. 
As noted by Panchen and Walker (1960, p. 328), the horizon 
is close to the base of the Carboniferous Limestone Series. The 
only amphibians of greater age, apart from the ichthyostegids 
of East Greenland, are a few small lepospondyls and the uni- 
que Oiocratia skull from the underlying Oil Shale Group of the 
Calciferous Sandstone Series of the Scottish lowlands. The 
amphibian remains now under study from West Virginia are 
from horizons near the summit of the Mississippian, and hence 
later in time of deposition than Gilmerton. 

DESCRIPTION 

Huxley's original figure shows the general character of the 
specimen (his pi. XI, fig. 3), although the artist has taken cer- 
tain liberties with it (circular objects which he supplied in 
the head region suggest orbits, but the view here is ventral ; 
the vertebral column which he pictures in the trunk region was 
drawn largely from his imagination, not from the material). 
A more accurate representation is given in my Plate I, A (in 
which, however, the squamation is omitted) ; details are shown 
in Figures 1 and 2. The skeleton (BMNH No. 30534) is pre- 
served on a series of small slabs which for the most part fit 
together without apparent gaps ; almost the complete animal 
was present in articulated fashion. Skull, jaws and trunk are 
seen in ventral view; the tail is seen from the left side. De- 
composition appears to have set in to some degree before burial, 
so that most of the belly wall and its armor of scales, broadly 
visible the length of the trunk, lies mainly to the (morphological) 
right side of the column. The total length as preserved is 117 
cm. As Huxley notes, the specimen was in "a very indifferent 
state of preservation," and its natural condition was not 
improved by preparation, a century ago, of a rather crude na- 
ture. When studied by Watson much of the structure of the 



ROiMER : LABYRINTIIODOXT IMIOLIDOGASTKR 133 

tail and i)(4vie area was visible, as well as the surface of the 
under side of the head and shoulder region. Mr. Ri.xon's further 
preparation dealt mainly with the trunk vertebrae and part 
of the dorsal surface of the head. Since the skull is poorly pre- 
served and little can be told of the anterior i)art of the body. 
I shall reverse the customary sequence in description, and 
begin with the axial skcldon of the tail, leaving skull and jaws 
to the last. 

Tail. Nearly the coinpjcte tail is present. Parts of three 
vertebrae are missing in the gap between the block contaiiung 
the pelvic region and those containing the rest of the tail, and 
another somewhat farther back where a surface chip is missing 
from the block. Allowing for these missing areas, thirty-one 
eaudals are present back of the position of the presumed sacral 
vertebra. The tail is comparable in length with that seen in 
ichthyostegids, on the one hand, and various temnospondyls, 
on the other, but is shorter than that seen in many primitive 
reptiles and in the embolomere A^'cheria. 

It would appear that when the specimen was discovered 
the slab split in such fashion that the tail was immediately 
exposed. However, the split ran for the most part through the 
substance of the vertebrae, so that surfaces of the elements 
are but poorly seen. The net result is that interpretation of 
the material is difficult. In the figures, I have endeavored to 
outline the structures exactly as preserved, resisting the tempta- 
tion to give subjective restoration of obscure areas. 

As a result of the ]XJor condition of the material, it is difli- 
cult to tell which side of the tail we are looking at. On one 
margin are seen v\'edge-shaped neural arches from whicii neural 
spine.s slant diagonally backward; on the opposite nuirgin are 
almo.st identically shaj^ed intercentra and haemal spines. But 
which is which ? Watson believed that the view was from the 
left, so that, for example, in my Plate 1, figure A the neural 
arches and spines lie along the lower margin. My own conclu- 
sions, based on more evidence than was available to Watson, 
were at first that the view was from the opposite, right, side, 
basing my belief on the fact that the posterior trunk vertebrae 
are seen somewhat to the right of a direct ventral view, and that, 
hence, one would expect a continuation of this twist on toward 
the tail. Put the left half of the pelvic girdle lies uppermost 
and, most especially, the structure of the caudal vertebral ele- 
ments is reasonably interpretable only from the Watson point 



134 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 




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ROMER : LABYRINTHODONT PHOLIDOGASTER 135 

of view. Obviously, body and tail were sharply twisted on one 
another at the pelvic region. 

The vertebral structure of the tail, as Watson notes and illus- 
trates (1929, fig. 7), is intermediate in character between rhachi- 
tomous and enibolomerous typos. Well developed neural spines 
are present throughout the length of the tail. They are strongly 
inclined backward. They were obviously flattened, and even 
far posteriorly are seen to be square-tipped at their distal ends 
where well preserved. There is some suggestion that at the tip 
of the tail the two arches are not fused into a single spine, but 
in the condition of the material this is not certain. Little can 
be made out regarding zygapophyses or the transverse processes 
which one would expect on proximal caudals. 

The arch bases are massive, triangular structures, their ventral 
apices extending far down toward the bottom of the column. 
Their anterior and posterior margins are, where the surface can 
be clearly seen, raised ridges — the anterior margins more promi- 
nently defined — and the intervening areas somewhat concave. 

The intercentra, as said above, are mirror-images of the arch 
bases, triangular in shape as seen in side view, with dorsal apices 
extending up toward the top of the central region, and with 
bases occupying nearly the whole length of each segment ven- 
trally. Although nowhere is an intercentrum seen in end view, 
it is, as noted by Watson, improbable that a complete intercentral 
ring was present. Intercentra of this general type were already 
present in rhipidistian crossopterygians, were retained in most 
temnospondyls, and would be expected to be present likewise 
in ancestral anthraeosaurians. Firmly fused with the inter- 
centra are haemal arches which, like the neural spines, slant 
strongly backward. The most anterior ones are incompletely 
preserved, but a haemal spine appears to be present on the 
vertebra which I interpret as caudal two, and spines continue 
throughout the caudal series. Anterior ones are massively built ; 
beyond, however, they become shorter and more slender, and in 
the last third of the tail are reduced to rounded swellings below 
the intercentra. 

Most interesting of vertebral elements are the pleurocentra. 
When seen laterally in articulated position, the pleurocentrum is 
a long slender band curving diagonally downward and forward 
between the arch base and the intercentrum of the succeeding 
segment. In several instances in the tail the pleurocentra are 
seen somewhat out of position in the form of slender half-rings. 
Watson suggested that the presence of these fractional rings was 



136 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

due to breakage, and that in life each pair of half-rings formed 
a single unit, completely surrounding the notochord. However, 
the fact that a similar condition is also seen in several instances 
in the presacral column (not prepared at the time of Watson's 
study) strongly suggests that this "broken" condition is a 
natural one, and that in life the pleurocentrum, although com- 
pletely surrounding the notochord, ossified not as a single element 
but as two slender hemi-cylinders. This is a condition which 
might be reasonably expected as an early stage in the develop- 
ment of an anthracosaurian column from a primitive protorhachi- 
tomous one, and is seen as an ontogenetic stage in the diseo- 
sauriscid seymouriamorphs (Spinar, 1952, pp. 118-119, figs. 6-8). 
Posterior trunk vertebrae. A series of vertebrae on the slab 
containing the posterior half of the trunk and the hind limbs is 
well exposed in ventral view. Unfortunately, however, the neural 
arches are nowhere completely preserved, and the neural spines 
are not visible. The intercentra are large structures, comparable 
to those of typical rhachitomes, 10-11 mm wide at the ventral 
midline and tapering gradually toward their upper ends. An- 
terior and posterior margins are raised rims ; toward the upper 
ends, the narrowed lateral surface is a concave channel between 
the two rims. There is a rounded longitudinal ridge at the 
ventral midline, with a shallow pocket on each side and above 
each pocket a secondary longitudinal ridge. The intercentra are 
thin shells, and there was obviously a large persistent notochord. 
Little is seen of the upper termini of the intercentra. In some 
there is an indication of a notch in the posterior border, dorsally, 
for rib attachment. It was earlier believed that Pholidogaster 
was embolomerous in structure. This is not the case, for not 
only are the intercentra incomplete rings, but also there are no 
formed true centra. Instead, there are paired pleuroeentra. In 
no instance are they here seen in place ; they are displaced in 
various fashions, so that, fortunately, their structure can be 
readily made out. Each pleurocentral element, thin externo- 
internally and narrow anteroposteriorly, is curved so as to form 
an arc which in life came close, it would seem, to 180° ; un- 
doubtedly in the trunk, as can be seen clearly in the tail, the 
two pleuroeentra came close to joining one another dorsally and 
ventrally. In several instances the lower end as preserved is 
relatively broad, the upper end slender and pointed. Presuma- 
bly the lower end reached the ventral midline between successive 
intccentra. The upper end slanted forward along the back 



KOMEH : hABYRINTIIODONT PI lOLIDOCASTER 137 

margin of its proi^cr iiitcrcciitniin and narrowed to allow room 
for the pedicel of the arch, Avliich may have been developed 
somewhat as in the tail, although certainly not reaching as fai- 
ventrally. 

A number of ribs are preserved. The "lumbar" ribs are 
straight, slender and short, tyi)ieal lumbars iiaving lengths of 
about 15 mm, and one farther forward (about the tenth pre- 
sacral) reaching a length of 37 mm. The last precaudal inter- 
centrum preserved lies close to the midlength of the left femur ; 
it is a some^vhat stouter element than those preceding it. On the 
left side its posterior margin is strongly notched near its upper 
end. Projecting from this notch is a stout, truncate structure 
which is suggestive of a sacral rib-head; close beside it, and 
partially concealed by adjacent materials, is a leaf -shaped struc- 
ture which may well be the blade of a sacral rib. 

Anterior trunk vcrtchrae. Remains of the "thoracic" region 
are visible along the "lower" margin of the first postcranial 
block, but were completely obscured by the dermal armor prior 
to development in 1960. Preparation here proved, however, very 
difficult. Attempts at acid preparation were fruitless ; the dermal 
scales were closely apposed to the underlying bones and it was 
(and is) difficult here to tell the two materials from one another 
and both from matrix, and this region of the column is un- 
satisfactory. Nine intereentra, seen in ventral view, can be 
identified : they are, however, incompletely exposed and, an- 
teriorly, somewhat disarticulated. Swellings in the scale areas 
covering the block suggest the presence of concealed intereentra 
at the points marked by stars on Figure 1 A. Pleurocentra are 
poorly preserved. It is, of course, impossible to determine ac- 
curately the total number of presacral vertebrae ; but if the head 
has retained its connection with the column, the presacrals may 
be estimated at thirty-six — a reasonable number for a ]irimitive 
labyrinthodont. 

A number of ribs are seen at the lower margin of the block. 
None is complete. They are obviously longer and broader than 
the "lumbar" ribs seen on the block following posteriorly. The 
heads are expanded, although the nature of the articular surfaces 
is uncertain, and there are indications of expansion in breadtli 
distally. One rib is preserved for a length of about 40 mm, and 
is obviously far from complete. No neural arches can be seen 
in this series. 

Pectoral girdle and linih. The clavicles are exposed on their 



138 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

ventral surfaces.^ They are broadty expanded ventrally, with an 
essentially triangular shape and with a typical labyrinthodont 
sculptural pattern of radiating ridges. The left clavicle is 
complete; the right is missing a fraction of its posterior margin. 
Poor remains of the sharply upturned ascending process are 
present on both sides. The anterior part of the interelavicle is 
present ; it is seen between the two clavicles and a short distance 
back of them. The posterior part is absent, but a smooth impres- 
sion, probably giving nearly the complete outline, is present on 
the matrix. A sculpture pattern is seen over the ventral surface 
of the interelavicle where visible, except posterior to the (in- 
complete) right clavicle, where a smooth surface for apposition 
with that bone is seen. The margins of this smooth area indicate 
that in life the two clavicles were somewhat more broadly sepa- 
rated posteriorly than as preserved, the right clavicle having 
been pushed somewhat medially and anteriorl3^ A slender rod 
seen at the margin of the slab close to the left clavicle can be 
reasonably interpreted, as Watson suggested, as the stem of a 
cleithrum. It would seem that the girdle was, in all probability, 
fairly comparable to that seen, for example, in Archeria. Between 
cleithrum and interclavicular impression are obscure remains 
obviously belonging to the left scapuloeoracoid. A larger mass 
of broken material which presumably represents the right scapu- 
loeoracoid is seen at the (true) right-hand margin of the inter- 
clavicular impression and dorsal to the posterior end of that 
impression. 

There are no preserved remains of the left front limb (the 
slab does not include the area where its remains would be expec- 
ted). An impression on the matrix adjacent to the presumed 
remains of the right scapuloeoracoid indicates the position of 
part of the upper end of the right humerus, but the middle 
portion of the bone lay in the position of the crack separating 
the slab containing the head from that containing the anterior 
end of the trunk. On this second slab are preserved the lower 
end of the humerus and incomplete radius and ulna ; there are 
no traces of carpus or foot. The situation suggests a humeral 
length of somewhat under 5 cm; the lower end is 24 mm broad. 
The bone is seen from the ventral surface. There is a well 
developed entepicondyle, and an ectepicondylar surface separated 



1 A comparable isolaterl clavicle from Gilmerton is present in the Museum of 
Practical Geology (no. axvii/l-5B). 



ROMER : I.ABYRINTIIODOXT ]>IIOLIDOGASTER 139 

from the under side of the entepicondylar repiou by a loiif=fitiidi- 
nal ridge. Tlie ])oiie, as seen in end view, is considerably thick- 
ened above this point. There is no ossified ventral articular area 
for the radius, but there may have been in life a modest carti- 
laginous extension here. No entepicondylar foramen is seen, but 
the bone is somewhat crushed in the area Avhere this might be 
expected. 

The upper part of the ulna is preserved, and the distal part 
is represented by an impression. The olecranon was obviously 
unossified ; the shaft was 22 mm long, the upper end 5 mm 
wide ; the bone becomes more slender distally and the radial 
margin is somewhat concave. Much of the radius is present, but 
the lower part is incomplete, crushed and obscure. The upper 
articular surface has a width of 7 mm ; the length appears to 
have been about 24 mm. 

Pelvic girdle and limb. As AVatson notes, considerable informa- 
tion can be obtained regarding the pelvic girdle and limb. There 
is no trace of the right half of the girdle, but the left half is 
present, its outer surface exposed, and the ilium directed ' ' down- 
ward" toward the low^er edge of the slab. There is the long 
posteriorly-directed process of the ilium common to many very 
primitive tetrapods (further development shows it to be broader 
than in Watson's figure). The region in which one would expect 
a dorsal iliac process for articulation with a sacral rib is damaged. 
Most of the outline of the acetabulum is preserved ; the ischium 
is nearly complete; the pubis represented only by an impression. 

Both femora are present, the right running forward morpholo- 
gically beneath the column, the left turned upward; the left 
femur is seen in ventral view, the right from an anterodorsal 
aspect. The right femur as preserved is 46 mm in length, the 
left 51 mm. The width of the head is about 12 mm, the distal 
width the same, the slender shaft 5 mm in minimum breadth. 
The dorsal surface of the head, seen on the right femur, has 
the common pattern of primitive tetrapods : well-rounded in 
transverse section, and somewhat convex in outline proximally, 
the mid-point of the curve somewhat anterior to the line of the 
shaft. The exposed anterior aspect of the left femur shows the 
presence of a pronounced internal trochanter, with a distinct 
longitudinal depression developed along the anterior surface 
between the trochanter and the shaft proper. Unfortunately, the 
head region is imperfectly preserved, and little can be said except 
that there appears to be the usual ventral intertrochanteric 
fossa, bounded anteriorly by the internal trochanter. Distally, 



140 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

typical anterior and posterior condylar regions are readily dis- 
tinguishable on both femora, the posterior, as always, more 
prominent. The two condyles are separated dorsally, as generally, 
by a distinct longitudinal hollow. Ventrally, broad articular 
faces for the tibia are seen, facing outward and downward at 
about a 45° angle; the right femur shows that the end of the 
posterior condyle was (as frequently in labyrinthodonts) un- 
ossified. The anterior articular surface extends some distance 
up the shaft. Ventralty a deeply excavated popliteal space is 
seen, on the right femur, between the two condyles. A low but 
sharp adductor crest runs proximally up the shaft from the 
posterior margin of the popliteal space. Presumably it connected 
proximally with the internal trochanter, but preservation prox- 
imally is not good. On the w^hole, the femur is of a generalized 
and primitive type of the sort seen, for example, in the Pap- 
posaurus femur from the somewhat later Loanhead No. 2 Iron- 
stone (Watson, 1914) or in Archeria. 

The right tibia and fibula are seen from the anterior (extensor) 
aspect. The tibia has a length of 24 mm; the head, somewhat 
convex in outline, is 7 mm broad ; the shaft contracts to a width 
of 4 mm, then expands distallj^, where the width of the bone 
(partially covered by a metatarsal) appears to have been 9 mm. 
The fibula (as Watson notes) is, as in primitive tetrapods gen- 
erally, a longer and broader bone than the tibia, with a length 
of the right element of 28 mm, and widths of head (partially 
covered), shaft, and distal extremity of 8, 5 and 11 mm, re- 
spectively. As in labyrinthodonts generally, the distal articular 
surface curves broadly proximally toward its tibial margin, 
affording contact, presumably, with a proximal centrale as well 
as an intermedium. On the left side the tibia is not preserved; 
the element present is the fibula. Its length (as is that of its 
mate) is 28 mm. It appears thin because seen from its medial 
aspect. Distally the medial portion of the articular surface is 
exposed. 

As Watson notes, the tarsal region is difficult of determination. 
The left tarsus has been exposed since his studies. Preserved 
(partly as impressions) are a large proximal element and three 
more distally, above the heads of the metatarsals. Possibly these 
may represent an intermedium and fibulare, fourth centrale and 
tibiale ; but if so, we must assume that the distal tarsals and more 
distant centralia have been displaced and were possibly un- 
ossified. On the right side is a large element which (again) I 
tend to identify as an intermedium, and several smaller and 



ROMEK : LABYRINTIIODONT PHOLIDOGASTER 141 

rather obscure elements. On either foot three articulated meta- 
tarsals are present. This count is surely due to accidents of 
preservation, and not improbably the animal was pentadactyl. 
The three left metatarsals have lenj^ths as preserved (counting 
from the fibular margin) of 10, 9 and 8 mm (the second and 
third reach tlie edge of a fracture in the block and may have 
been slightly longer). Those of the left side (counting in the 
same direction) have lengths of 11, 11 and 12 mm. On the left 
foot a further, incomplete metatarsal is present alon^ide the 
distal end of the fibula. Both feet appear to be seen from the 
ventral aspect. The metatarsals are essentially flat and feature- 
less, but there is a suggestion of a slight dorsal arching of the 
bones along their lengths. The most medial toe of the right 
foot originally had three phalanges, with lengths, as seen in 
Watson's drawing,^ of about 5, 2+ and 1 mm. This toe has been 
partially removed, to exhibit a proximal phalanx of a second toe, 
7 mm long. Beyond this, Watson's figure indicates, there was 
formerly a second phalanx, about 4 mm in length, and a small 
terminal element. 

Ahdominal armor. The ventral armor is well preserved over 
most of the region between pectoral and pelvic girdles ; its 
general disposition may be seen in Huxley's figure 1. As typi- 
cally, the rows of gastralia on either side meet at a sharp angle in 
the midline. This midline can be traced from a point just prox- 
imal to the entepicondyle of the right humerus back, roughly 
parallel to the vertebral column, to a termination anterior to the 
head of the right femur. Along the anterior part of the trunk the 
midline lies but 10-16 mm to the right of the exposed vertebral 
centra; in the "lumbar" region, however, the midline arches 
to the left, to an extreme of 40 mm from the column, before 
curving back toward the pelvis. The squamation of the left side 
curved downward over the vertebrae and ribs. This area was 
partly destroyed during preparation of the column. The squam- 
ation of the right side, however, is fully exposed as far as it was 
preserved in the specimen when collected. Along the anterior 
part of the column the squamation extends outward l)ut 20-30 
mm from the midline, giving the diagonally-directed scale-lines 
a length of 25-38 mm. It is probable that the narrowness of 
the squamate area preserved here is due to post-mortem loss. At 
the middle of the back, breadth of the scale-covered area in- 
creases, and extends out some 50 mm to the far edge of the slab, 

1 The reduction is closer to X % than to the X % given in Watson's legend. 



142 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

giving a maximum length of scale rows, as preserved, of about 
70 mm. More posteriorly, the width of the scaled area decreases 
to about 20-25 mm a few centimeters in front of the pelvis ; as 
preserved, however, the scale rows here slant very strongly back- 
ward (perhaps due to post-mortem distortion) so that their 
lengths approach 50 mm. 

The general pattern of arrangement of the gastralia is seen 
in Huxley's figure 4. However, his illustration is rather more 
than "of the natural size," for in general the scales are but 
about 10-15 mm long. They are essentially oat-shaped, with 
greatest widths about one-third the length. Their apparent 
width is less ; posterior to a longitudinal ridge, the surface of 
each scale is overlapped by its neighbor, so that the average ex- 
posed width is little over 2 mm. As Huxley shows (but generally 
to a somewhat greater degree) the ends of the scales overlap 
their neighbors in the same scale row. The maximum number of 
scales in a given diagonal row does not appear to exceed ten 
or so, even in the broadest preserved area of squamation. The 
central element in each row is roughly U-shaped, with the two 
arms of the U diverging posteriorly from one another at about 
60° ; anteriorly, each median scale sends forward from its 
rounded central area a tongue-shaped process which underlaps 
its anterior neighbors. 

Skidl. The skull has been crushed flat in such fashion that 
the jaws were pushed somewhat to the right, the skull to the 
left. A limited amount of the dermal roof is visible on the 
under surface (Fig. 2). At the "lower" margin is seen a frag- 
ment containing most of the left jugal. Its posterior end is 
represented only by an impression, and hence its relation to 
the quadratojugal is not clear. The ossification center is close 
to the anterior end of the part preserved. Near the anterior 
end of the jugal are fragmentary remains of the lower margin 
of the left maxilla ; a few small teeth are visible. The lower 
margins of both premaxillae are visible. The teeth are for the 
most part absent, but nearly the whole length (of about 7 mm) 
of a large tooth is preserved, and there are obscure remains of 
several other teeth and alveoli. Lying near the right clavicle 
is the displaced right quadrate, and a broken strip of bone 
anterior to it may be the right quadratojugal. 

The dorsal surface of the skull was embedded in a mass of 
ironstone. At my request Mr. Rixon cleaned, with considerable 
difficulty, the anterior portion of this surface, revealing a series 
of crushed and displaced fragments. A further area cleaned, in 



ROMER : LABYRINTHODONT PIIOLIDOG ASTER 



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144 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

the left posterior region of the roof, exposed a mass of crushed 
bone fragments impossible of interpretation, and no attempt was 
made to clean the rest of the roof, since it is highly improbable 
that the results would be worth the effort. Anteriorly (Fig. 3), 




Figure 3. Dorsal view of anterior part of head of type. X V^- Abhrevia- 
tions: a, angular; d, dentary; I, lacrimal; m, maxilla; n, nasal; pm, pre- 
maxilla ; sa, surangular. 



the right premaxilla is apparently present in toto, and a portion 
of the left is seen as well. Posterior to them are good-sized 
sculpture plates representing much of the nasals, and to the left 
of the left nasal much of the left lacrimal and part of the left 
maxilla are preserved. A fragment posterolateral to the right 
premaxilla may be an incomplete right lacrimal ; a tooth-bearing 
strip of maxilla is seen posterior to this. I cannot be sure of the 
nature of any of the more posterior skull roof fragments. The 
acid preparation has preserved the sculpture pattern in excel- 
lent style. There is little evidence of radial arrangement of the 
ornament, which consists essentially of subcircular pits sur- 
rounded by well-raised ridges. 

A considerable amount of bony material, presumably pertain- 
ing to the palate and braincase, can be seen on the ventral surface 
between the jaws, but little of it is interpretable. Paralleling 
the right jaw ramus is a long strip of denticulate bone which is 
presumably part of the right pterygoid, and opposite this a 
second dentate area presumably belonging to the left pterygoid. 

Lower jaw. Nearly the entire external surface of both lower 
jaws is exposed on the ventral aspect of the cranial slab. The 
left jaw as preserved measures 186 mm from symphysis to end 



ROMEU : LABYRIXTIIODONT IMIOLIDOGASTER 145 

of artieulai'; one <>aiiis stroiijily tlic impression that anterior and 
posterior ]iortions have been pulled somewhat apart. The right 
jaw appears much shorter, measuring 140 mm in length as pre- 
served, due to the fact that it was so broken post-mortem that 
the posterior portion has pushed forward under the anterior 
part. Very probably the actual length in life was on the order 
of 160 to 170 mm. In the left ramus the distortion is such that 
the splenial elements, which curved medially toward the ventral 
surface in life, are flattened into the plane of the angular and 
dentary, thus giving an impression of greater than true depth. 
Several fragments include most of the dentary, but nowhere 
is its alveolar margin present. The left surangular is nearly 
completely covered by a plate including most of the jugal. Over 
much of the posterior part of the angular region the surface is 
eroded. On the dorsal side (not figured) the articular surface 
is nearly completely visible ; it is, as in many primitive forms, 
divided into two areas which are at nearly right angles to one 
another and separated by a rounded ridge. Anteromedially, 
there is here seen a ridge representing the posterior end of the 
prearticular and, below^ this, the thickened rounded ventro- 
medial margin of the angular. 

On the right side, as noted above, anterior and posterior seg- 
ments of the broken jaw over-ride one another. The anterior 
segment includes splenial, postsplenial and part of the dentary. 
The dentary is so broken that much of its posterior portion is 
turned over to appear on the upper surface of the slab. Here 
the middle portion of the tooth row is present, although poorly 
preserved. Of the posterior segment, the greater part of the 
angular is seen on the lower aspect. At the back, crushing is 
such that the articular is seen in posterior view, but preserva- 
tion is poor. Dorsally is seen a small portion of the angular 
and the overturned upper portion of the surangular, including 
its curved upper margin; much of the extent of this bone ap[)ears 
to have been lost from the margin of the .slab. 

Our knowledge of the lower jaws of the type is, thus, confined 
almost entirely to the outer surface. The pattern obviously 
conforms to that common to many primitive or generalized 
labyrinthodonts, and shows no diagnostic character of any sort. 

The Edinhurfjh skull and jaws. Watson (1929) identified as 
probably belonging to PhoUdogaster a skull in the Royal Scottish 
Museum (no. 1.10.561) which, from the character of its matrix, 
appears to come from the Gilmerton ironstone. I see no reason 
to dissent from this identification. The size and .shape are 



146 



BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 



appropriate. I have estimated the jaw length in the type as about 
160-170 mm; the length of a jaw associated with this Edinburgh 
skull is 163 mm. As can be seen, the skull is diagnostically 
anthraeosaurian, as would be expected from the "subanthraco- 
saurian" nature of the vertebral column. The sculpture of the 
skull roof is more sharply defined in the type skull, but this is 
attributable to the acid preparation of the type, whereas the 
Edinburgh specimen is a split block, in which sculptured ridges 
are seldom sharply preserved. 





Figure 4. Dorsal and ventral views of the Edinburgh skull, modified from 
the restoration by Watson. Abbreviations: ec, ectopterygoid; f, frontal; 
it, intertemporal; p, parietal; pf, postf rental; pi, palatine; pp, postparietal ; 
prf, prefrontal ; pt, pterygoid ; st, supratemporal ; t, tabular ; v, vomer. 



I reproduce (Pig. 4) AVatson's attempted restoration of this 
skull, with some additions resulting from restudy of the specimen. 
The skull table is comparable to that of embolomeres, particularly 
in the fact that, as in that group, the well developed intertemporal 
extends forward to nearly completely separate postfrontal and 
postorbital. I believe the tabular-postparietal suture can be 
made out on the right side in approximately the position indi- 
cated by Watson. The outer margins of the supratemporal and 
tabulars curve downward toward the plane of the cheek, but 
the fact that the right cheek has broken off from the table 
along the plane of suture between squamosal and table indicates 
the presence of the zone of weakness here expected in anthra- 
cosaurians. On the right side of the facial region there are 



ROMER : LAHYRINTIIODONT PIIOLIDOQASTER 147 

indications of part of the .sutural pattern, and 1 have indicated 
sutures here (with doubt) as broken lines. It seems probable 
that the lacrimal was excluded from the orbital rim by a pre- 
frontal-jugal contact. There is a break parallel to the tooth row 
which Watson has interpreted as the upper border of the maxilla. 
1 rather think, however, that this break lies alony the length 
of the lateral line groove, and that anteriorly the maxilla ex- 
tended farther dorsally. 1 can make no more of the palatal 
aspect than the features shown in Watson's reconstruction. 

The right lower jaw (Fig. ")) is completely preserved as to 



Figure 5. Inner view of the right iiiaiidiblc of tlie Edinburgli specimen. 
Anteriorly, the inner surface is absent, so tliat indications of sutures of 
elements of outer surface are seen. X %■ Abbreviations : a, angular; d, 
dentary ; pos, postsplenial ; sp, splenial. 



length, but crushed and partially covered by the skull. It is 
slender anteriorly, gradually deepening posteriorly. Little can 
be made out regarding the external surface except that anteriorly, 
where the inner surface of the jaw is missing, there can be seen 
indications of sutures between the dentary and a narrow splenial 
and, more posteriorly, a second splenial element. The inner 
surface is preserved posteriorly. There is a strong medial proc- 
ess extending inward below the articular region, apparently 
corresponding to the region seen in ventral view as part of the 
crushed right jaw of the type. The inner face of the jaw below 
and anterior to the articular region is deep ; its upper margin, 
forming the inner rim of the adductor fossa, bears a low but 
definite ridge. Farther forward, little can be made out of the 
inner jaw aspect, but enough is present to show that the large 
fossae in this region which are characteristic of embolomeres 
were not present. 

Lower jaw teeth are not seen, but maxillary teeth are pres- 
ent. As in the type they are numerous, small and slender ; when 
completely preserved they are seen to be slightly recurved at 
their tips, and there is some indication of striation in the basal 



148 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

part of the teeth. They are spaced 3.5 to 4 mm apart. It would 
appear that replacement was actively underway at the time of 
death, with empty alveoli between most of the teeth present. 
There is no indication of a developed canine region, but such 
teeth as are well preserved suggest a region of maximum length 
of about 10 mm at a point somewhat anterior to the midpoint 
of the maxilla. Presumably the tooth row (including empty 
alveoli) included (as Watson's figure suggests) about 30 teeth. 

DISCUSSION 

Restoration. Because of the unique nature of this skeleton, I 
have thought it worth while to attempt a restoration — this 
despite our inadequate knowledge of certain features (PI. 1, B). 
Uncertainties regarding skull structure have been noted earlier. 
The endochondral shoulder girdle and cleithrum are incom- 
pletely known, but it is reasonable to restore these elements 
according to the common pattern found in forms removed as far 
from one another as the embolomere Archeria and the rhachitome 
Eryops. The manus is missing, the ribs are incompletely known, 
and few data are available regarding presacral neural arches, but 
we cannot go far wrong in restoring absent elements in the fash- 
ion common to most labyrinthodonts. With his short limbs, 
long trunk and well developed tail, PhoUdogaster was, obviously, 
primarily a water-dwelling form as, presumably, were all primi- 
tive labyrinthodonts. 

Phylogenetic position of PhoUdogaster. In many regards 
PhoUdogaster is a rather generalized and essentially primitive 
labyrinthodont. The specimen is well ossified and obviously ma- 
ture. With a length of about 117 cm — less than four feet — it 
is a much smaller animal than such well known Carboniferous 
labyrinthodonts as the large embolomeres of the Pteroplax- 
Eogyrinus group and such a large loxommid as Megalocephalus. 
On the other hand, it is not far from the size of the ancient 
ichthyostegids, and labyrinthodonts Avith proportions similar to 
those of PhoUdogaster occur at various later levels of the Carbon- 
iferous. 

Apart from the vertebral centra, the postcranial skeleton shows 
few diagnostic features. The broadly triangular clavicular ])lates 
are presumably primitive in character. Such plates are charac- 
teristic of embolomeres and seymouriamorphs in later times, but 
broad clavicular plates are present in some seemingly primitive 
temnospondyls (as well as advanced forms) and are seen in tlie 



ROMEK : LABYRINTIIODONT PIIOLIDOGASTER 149 

arcliaic ichthyostegids. The iiilorclavicle is luifoi-tiinatoly incom- 
plete; it was obviously lou^, hut elongation is fouml in sdiiic 
temnospondyls as well as in anthracosaurs, and one cannot tell 
whether or not the long stem essentially diagnostic of the later 
group was present. The ilium shows a long i)osterior process 
plus, apparently, the small ascending blade foi- sacral rib articu- 
lation. This structure has long been recoguized as one found in 
the embolomeres and such further anthraeosaurians or seymouria- 
morphs as Diplovfrfehron and Discosauriscus. But since we now 
know that this type of ilium was already developed in iehtliyos- 
tegids, this feature, again, is not a diagnostic one. Too little is 
known of limbs in early labyrinthodonts to make profitable an 
attempt at diagnosis on the basis of limb bones. 

The vertebral structure, however, is almost unique. As de- 
scribed above, the intercentra are the prominent elements of the 
central region — massive structures, although incomplete dor- 
sally, which form the main supports of the neural arches. The 
pleurocentra have the form of paired half-rings, surrounding the 
notochord; they are slender but extend the full depth of the 
central region. 

It is entirely reasonable to assume that the vertebral structure 
of PJwlidogaster represents an initial stage in the development of 
the anthracosaurian vertebral column, leading to the structures 
present in embolomeres, seymouriamorphs and typical reptiles. 

Because of the prominence of the embolomeres in collections 
of Carboniferous amphibian materials, it was at one time assumed 
that this type of vertebral structure was a basic one for laby- 
rinthodonts ; that there had been derived from this, on the one 
hand, the rhachitomous and stereospondylous types, in which 
pleurocentra became reduced and the intercentrum became 
dominant, and, on the other hand, a series in which the ring- 
shaped embolomerous intercentrum was progressively reduced, 
thus leading to seymouriamorphs and reptiles. 

It has, however, become apparent in recent decades that the 
embolomeres were far from being the sole labyrinthodonts in the 
Carboniferous. It now .seems clear that, despite their retention 
of a number of primitive features, the embolomeres are merely a 
subgroup of one of the two major lines of labyrinthodont evolu- 
tion — the Anthraco-sauria ; a parallel radiation of rhachitomous 
forms was also taking place during the Carboniferous. 

As a result, I proposed in 1947 an alternative scheme of laby- 
rinthodont evolution — one in which the ancestral type possessed 
vertebrae which were not embolomerous but proto-rhaehitomous 



150 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



(Fig. (')). Typical crossopterygians, from which labyrinthodonts 
may be reasonably derived, have in many instances large wedge- 
shaped intercentra and very small paired pleurocentra, situated 
dorsally near the lower margins of the neural arch. To develop 
from this the temnospondylous type of vertebra seen in the 
Rhachitomi requires no change except some modest increase in 
the size of the pleurocentra to strengthen the column by filling 





© Q]fe) 



Embolomeri 



Seymouriamorpha 



® Da ® °'^'° 

t 



to Rhachitomi 




men 



Schizomeri 



.^%, 



Primitive 
condition 



Figure 6. Suggested evolutionary series of anthracosaurians, with a 
typical vertebra representing each stage or group. In each ease the vertebra 
as a whole is seen from the right side; at the left the pleurocentra (or 
centrum) shown in end view; at the right, the intereentrum in end view. 



ROMER : LABYRINTIIODOXT lMIOLirX)GASTER 151 

out the gaps in the dorsal part of the central rep^ion where ossi- 
fication had been lackin<>'. To develoj) an aJithracosanrian type of 
vertebra would denuiiid a major development of the ))leurocentra. 
They should expand and coalesce to foi-m a rin<r-sliaped true 
centrum. Beyond this stagfe, completion of a rin<r-shaped struc- 
ture of the intercentrum as well would lead to the em])olomerous 
condition as a side line; on the other hand, reduction of the 
intercentrum would lead to the conditions seen in seymouria- 
morphs and typical reptiles. 

Support for this theory of vertebral evolution was given by 
Jarvik's description (1952) of the vertebral column of ichthy- 
ostegids. In them, as in many crossopterygians, the pleurocentra 
are very small, dorsally placed, paired elements. To be sure, the 
ichthyostegids are probably somewhat otf the main line of laby- 
rinthodont evolution, but the presence here of proto-rhachitomous 
vertebrae is strongly suggestive of the general scheme of vertebral 
evolution which I had advocated. 

Further support of this theory is afforded by the vertebral 
condition of Pholidogastcr. If we are to form a true centrum 
from the small, dorsally placed pleurocentra of an ancestral 
crossopterygian, downward growth, toward the bottom of the 
column, of these paired elements is the first change to be expected 
— this to be followed later by a fusion of the two pleurocentra 
into a complete, true central, ring. This theoreticalh' expected 
stage is perfectly exemplified in the two half-rings of the 
Pholidogastcr centrum. The assumption that this condition is 
phylogeneticalh^ antecedent to the formation of a true centrum 
is reinforced by the ontogenetic condition described by Spinar 
(1952, pp. 118-119, figs. 6-8) in the seymouriamorphan family 
Discosauriscidae. Here the larger specimens show a complete 
true centrum ; but smaller and more immature individuals show 
paired hemicylinders corresponding closely to those of the mature 
Pholidogastcr. In the older individuals the two hemicylinders 
fuse ventrally and, still later, dorsally, to complete the mature 
central structure. 

Although the attribution of the Edinburgh skull to Pholido- 
gastcr is not capable of absolute proof, the pliylogenetic impli- 
cations of the structures seen in this skull are in perfect harmony 
with those derived from vertebral structure. The proto-anthra- 
cosaurian build of the Pholidogastcr vertebrae call for the pres- 
ence of a skull with anthracosaurian attributes; the definitely 
anthracosaurian nature of the Edinburgh skull calls for a 



152 BULLETIN : MUSEUM OF COMPARATR^ ZOOLOGY 

vertebral column of anthracosaurian or proto-anthracosaurian 
build. 

That the Edinburgh skull is anthraco.saurian cannot well be 
doubted. The tabular "horns" are of modest size,, and are not, as 
Panchen and Walker (1960) have pointed out, of the long-, 
pointed embolomere type ; such structures are quite surely spe- 
cializations of the embolomeres, and not to be expected in general- 
ized anthracosaur ancestors of seymouriamorphs and typical rep- 
tiles as well as embolomeres. Four diagnostic features may be 
expected in the skull of an ancestral anthracosaurian: (1) A 
tabular of good size which, as emphasized by Save-Soderbergh 
(1935) and Steen (1938), articulates with the parietal ^ — this in 
contrast to the reduced tabular of temnospondyls. Such a tabular 
is present in Pholidogaster. (2) A loose attachment of cheek to 
skull table with, posteriorly, a wedge-shaped otic notch. Current 
(and reasonable) belief as first advocated by AVatson (1926) is 
that this is a primitive situation, retained from the fish stage ; 
later anthracosaurians leading to seymouriamorphs and typical 
reptiles have modified this structure, but it is characteristically 
retained in embolomeres. In theory, the ancestral temnospondyl 
may have had this structure as well, but fusion of cheek and 
table and development of a rounded rather than a wedge-shaped 
otic notch obA'iously occurred at an early stage in temnospondyl 
evolution. The Edinburgh skull is primitive in construction, but 
the Gilmerton deposits are fairly well up in the Lower Carboni- 
ferous, and the time element speaks strongly for the Anthra- 
cosauria here. (3) In rhachitomes, postfrontal and postorbital 
are broadly connected back of the orbit, and the intertemporal, 
when present, is widely separated from the orbital rim. In 
embolomeres, in strong contrast, the intertemporal pushes toward 
the orbit so that there postfrontal and postorbital barely touch 
one another. In reptiles the intertemporal is normally absent 
and in seymouriamorphs it is reduced, so that a fair area of 
postfrontal-postorbital contact is developed. But the contact is 
still narrow in many seymouriamorphs and the embolomere con- 
dition may be reasonably regarded as primitive for anthraco- 
saurians. The Pholidogaster intertemporal is emphatically of the 
type of the presumed anthracosaurian ancestor. (4) In all typical 
rhachitomes, including the loxommids (and in the ichthyostegids 
as well), the muzzle is broadly rounded and on the palatal aspect 
the nares are widely separated, with between them broad plate- 
like vomers bearing a prominent tusk-pair. In embolomeres, in 



ROMER : LABYRIXTIIODOXT PIIOLIIX)flASTEH 153 

contrast, tlie iiares are close too-ether in the narrow snout, sep- 
arated only by narrow straj)-sliaped vomers which lack tusks. 
Primitive reptiles show this same condition, which can hence be 
reasonably regarded as i)rimitive for anthracosaurians. This 
pattern is present in the Edinburgh skull, further reinforcing 
belief as to its pertinence to the Anthracosauria. Too great 
reliance, however, should not be placed on this last feature, for 
it is obviously correlated in considerable measure with snout 
shape, and seymouriamorphs with broadly rounded muzzles ap- 
proximate the rhachitome condition. 

In sum — the vertebral construction of the type and diagnostic 
features found in the Edinburgh skull indicate that in this 
Gilmerton amphibian we are dealing with a primitive nieml)ci' 
of the anthracosaurian group of labyrinthodonts. 

Lahyrinthodont classification. In 1947 I reviewed the Laby- 
rinthodontia at some length, and established a classification based 
on all evidence then available. A major cleavage was made into 
two groups: Temnospondyli (including typical rhachitomes and 
stereospondyLs, the loxommoids and ichthyostegids)and Anthraco- 
sauria (including the embolomeres and forms leading to reptiles, 
with the semouriamorphs dangling, so to speak, on the amphibian- 
reptilian boundary). This dichotomy was based to some degree 
upon cranial characters of the sort discussed above, but ])rimari]y 
on divergence in vertebral structure — continued emphasis on 
the intercentrum among the temnospondyls, in contrast to a 
strong trend among anthracosaurs toward development of a 
typical centrum from the tiny paired pleurocentra of ancestral 
forms. 

Various advances made during the decade and a half since this 
essay at classification suggest that reappraisal of the situation 
may be in order. The basic concept of a division into temnospon- 
dyls and anthracosaurians appears to have been reinforced hy 
later discoveries, including the presence of proto-rhachitomous 
vertebrae in the ichthyostegids, as noted above, and of rliachi- 
tomous vertebrae in the previously doubtful loxommids (Baird, 
1957). 

Perhaps the one advisable major change would l)e the separa- 
tion of the Ichthyostegalia as a third, minor but distinct, 
lahyrinthodont group. To be sure, my inference that their 
vertebrae were rhachitomous has been validated, and they agree 
with the temnospondyls rather than anthracosaurians in fusion 
of cheek and braincase. a rounded otic notch, and broad vomers. 
But even Jarvik's preliminary descriptions show such a series 



154 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

of primitive characters that it is difficult to associate the ichthyo- 
stegalians closely with the more advanced temnospondyls of later 
times. Further, currently accepted tenets assume that the inter- 
temporal was part of the ancestral skull pattern of labyrintho- 
donts; its absence in the ichthyostegids suggests that they were, 
even at this early stage, somewhat of a side line. Accordingly, 
it is perhaps preferable to consider the ichthyostegal forms as 
a third, distinct group of labyrinthodonts, as follows : 
Superorder (or Subclass) Labyrinthodontia 
Order (or Superorder) Ichthyostegalia 
Order (or Superorder) Temnospondyli 
Order (or Superorder) Anthracosauria 
I shall refrain here from discussion of the temnospondyls, 
although work being done at present, by Baird and Carroll, for 
example, suggests progress toward sorting out true phyletic lines 
among the Rhachitomi in preference to the somewliat artificial 
grouping which I used in my 1947 classification. With regard 
to the ichthyostegalians, it is possible that with further knowledge 
the East Greenland forms will prove to be but one, possibly aber- 
rant, subgroup of an archaic group which will also include forms 
more directly ancestral to later temnospondyls and anthraco- 
saurians.^ It is pleasant to find that my suggestion (put forth 
in 1945) that Otocratia is related to the ichthyostegids is sup- 
ported by the finding of a comparable otic construction in an 
East Greenland genus (Jarvik, 1952). However, my further 
suggestion that the colosteids of the Pennsylvanian are much 
evolved ichthyostegids has not gained support either from new 
materials or from the opinions of my colleagues. 

Our present concerns are with the anthracosaurians (Fig. 6). 
As I pointed out in 1947, the major evolutionary event in early 
anthracosaurian history must have been the development of a 
complete ring-shaped centrum from the primitive, small, paired, 
pleurocentral elements, the intercentrum remaining persistently 
large. Once the true centrum evolved, further evolution could 
have proceeded in two directions — on the one hand, to the 
embolomeres with development of a ring-shaped intercentrum, 
and, on the other, to seymouriamorphs and typical reptiles with 
reduction of the intercentrum. In Pholidogaster we have a 
half-way stage in the development of a centrum, with the ring 



1 I am soiiH'tiines tempted to speculate that the ichthyostegid skull pattern may 
be related to the peculiar arranjreinent seen in niierosaurs, but there is, of course, 
not the slightest positive evidence for such a belief. 



ROMER : LABYRINTHODONT PHOLIDOGASTER 155 

completed spatially, but consisting of two discrete, pleurocentral 
halves. At the moment there is no other typical anthracosaurian 
known to me which has such a structure as an adult, although 
rather surely Pholidogastcr had predecessors, contemporaries and 
possibly successors exhibiting this structural stage. As noted 
earlier, Spinar (1952, fig. 6, etc.) figures specimens of Disco- 
saurisciis (Discosaurus) in which the centrum is in the form 
of two "pleurocentral" half -rings, and Credner (1893) also 
figures this condition. However, as Spinar clearly demonstrates, 
we are here dealing with larval forms ; the adult was a seymouria- 
morph, in which there was a complete central ring. 

Despite the lack of known relatives, it seems reasonable to 
consider Pholidogaster as representative of a stage in anthraco- 
saurian evolution which may be reasonably termed the sub- 
order (or order) Schizomeri — the name referring to the "bro- 
ken" appearance of the pleurocentral ring. 

Vertebrae with a construction of this same sort are described 
by Eaton and Stewart (1960) in Hesperohe7'peton, a tiny 
amphibian from the Pennsylvanian of Kansas. They consider 
this form as the type of a new order, the Plesiopoda. I hesitate, 
however, to use this term for the stage in anthracosaurian evolu- 
tion represented by Pholidogaster. The skull of Hesperohcrpcton, 
as described by Eaton and Stew^art, departs wildly not only 
from that of the anthracosaurians but from that of any known 
labyrinthodonts ; the pectoral limb is equally aberrant and seem- 
ingly primitive and fish-like, and the ordinal term has reference 
to foot structure, not to vertebral type. Possibly Hesperoherpe- 
ton is a larva whose metamorphosed adult would have had a more 
normal labyrinthodont structure ; again, this form may represent 
an aberrant side branch from the schizomeran stage of anthraco- 
saur evolution ; still again, it may represent an independent 
group developed from ancestral forms in parallel fashion to the 
anthracosaurs as regards vertebral structure. 

Next above the schizomeran level should be one in which the 
two pleurocentra should have fused to form a complete ring 
centrum, but in which there persisted an intercentrum incom- 
plete dorsally, but still retaining full height from the bottom 
level of the column to an articulation with the neural arch. 
Certainly, considering the radiation in the later Carboniferous 
of embolomeres, seymouriamorphs and true reptiles which de- 
veloped from forms in this structural stage, animals of this 
sort must have evolved before the close of the Mississippian. 



156 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

There are, however, few described specimens which appear to 
fall in this category. Somewhat comparable vertebrae from the 
Upper Carboniferous Joggins tree stumps of Nova Scotia 
occur on a slab containing a fragmentary skull described 
by Steen as Dendryazousa (Steen, 1934, fig. 17). As described, 
however, this skull fragment is not of an anthracosaurian type, 
but in this material, juxtaposition is no guarantee of association, 
and the vertebrae might perhaps belong to the anthracosaurian 
termed Calligenethlon (Steen, 1934, pp. 484-486, figs. 18, 19, 
20 B, pi. 2, fig. 1). To add to the confusion, it is quite possible 
that these animals trapped in hollow stumps may be immature 
and hence incompletely ossified; a "grown-up" Calligenethlon, 
for example, may have been a true embolomere. On somewhat 
safer grounds may be the materials described from the Pennsyl- 
vanian of Nyfany by Fritsch (1889, pp. 11-13, pis. 50, 52, 53; 
cf. Steen, 1938, p. 239) as Diplovertehron^ (although even here 
possible conditions of immaturity cannot be ruled out). In 
Diplovertehron the vertebrae, as seen in side view, appear to be 
those of an embolomere, Avith both intercentrum and true cen- 
trum parallel-sided structures extending full height to the neu- 
ral arch base. In end view, however, the intercentrum is incom- 
plete dorsally; the embolomere condition is not attained. 

This stage, albeit imperfectly known at present, seems clearly 
defined and should be named. A name derived directly from 
Diplovertehron might be confusing (as well as lengthy) ; Diplo- 
meri (by analogy with Embolomeri) may be utilized as a 
subordinal term for this stage, with Diplovertehron used, provi- 
sionally, as a type genus until a more ancient, more truly 
ancestral tj^pe be described. 

Unless the evolution of a ring centrum occurred more than 
once, in parallel fashion, among early anthracosaurs, the Diplo- 
meri were a group from which not merely embolomeres but 
seymouriamorplis and typical reptiles have been derived.' The 
pattern of evolution beyond the diplomerous .stage may have 
been complex. Whether or not the Seymouriamorpha are to be 
considered reptiles or amphibians remains a moot ])oint. In 
this group the Discosauriscidae, as Spinar (1952) has shown, 



1 Drs. .lanu's and Mar^'aret r.roiijrh iiiforiii me that certain iiialfi-ials sdinctinu's 
assigned to this gemis (as well as tluise of SdlciwdontKiiiriis) are iirdjierly to he 
assigned to (ieiihiirdslcgus. 

-I hoi)0 to return at a later date, after a deseriidion of the cranial structure of 
the niicrosaur Pantylus, to a discussion (contra) of the h,\ potliesis that part, at 
least, of the reptiles were derived from lepospoudyls. 



ROMEK : LABYRINTIIODOXT IMIOLIDOGASTER ].')7 

have a gilled larva ; but it is not impossible that amniote patterns 
of development may have already been present in the early 
embryonic stag:es of such a form. In the partially reduced inter- 
centra, the Seymouriamorpha show a sta<?e of vertebral evolution 
to be expected in rejjtile ancestors; but the Ijroadly-developcd 
otic notch of typical seymourianiorphs shows a (level()])nieiit 
hardly to be expected in reptilian ancestors. Possibly we have, 
in such animals as Grphyrostegos, a line parallelin<? the sey- 
mourianiorphs and leadinp: more directly to later reptile gfroups. 
I trust that work on Pennsylvanian faunas undertaken by Drs. 
James and Margaret Brough and others will shed light on this 
important area. It is, however, beyond the proper limits of the 
present discussion. I shall at the moment follow this classifica- 
tion : 

Order (or Superorder) Anthracosauria 

Suborder (or Order) Schizomeri. Centrum formed 
of two discrete half -rings; intercentrum very large, 
but not complete dorsally. Typical incised otic 
notch, cheek loosely articulated with skull table. 
No coracoid ossification. Ilium primitive, as in 
embolomeres. 
Suborder (or Order) Diplomeri. Centrum a complete 
ring ; intercentrum large, but not complete dorsally. 
Otic notch primitive. No coracoid ossification. Ilium 
as in embolomeres. 
Suborder (or Order) Embolomeri. Both centrum and 
intercentrum complete rings. Otic notch primitive. 
No coracoid ossification. Ilium persistently primi- 
tive. 
?Suborder (or Order) Seymouriamorpha. Centrum 
complete, but ossified intercentrum, while persist- 
ently large, not extending upward to neural arch. 
Cheek and table fused, otic notch highly developed. 
Ascending and posterior processes of ilium joined 
to form an iliac blade. Separate coracoid ossifica- 
tion. 
In the discussion above I have made no mention of amphibian 
groups, recent or fossil, other than the Labyrinthodontia. It 
has generally been considered that the Anura are related in 
some fashion to the Labyrinthodontia, and Watson (1940) advo- 
cated descent from Amphihamus of the Pennsylvanian, a form 
obviouslv related to the rhachitomes. It was on this account that 



158 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

I erected, in 1947, a subclass Apsidospondyli to include labyrin- 
thodonts and frogs. Subsequent work by Gregory (1950) 
appears to show that Amphihatnus is actually a rhachitome, but 
the possibility of this does not exclude a rhachitomous origin for 
the Anura. In a recent paper, however, Parsons and Williams 
(1963) point out various features possessed in common by 
frogs and urodeles and suggest a common origin for the two 
groups. If this proves to be the case, the labyrinthodonts will 
have no descendants except the reptiles, and the term Apsido- 
spondyli is perhaps redundant. 

Although I fail to be convinced by Jarvik's arguments for a 
separate origin of urodeles from fishes (Romer, 1962; cf. Thom- 
son, 1962), the fact that we find throughout the Carboniferous 
and early Permian varied series of small, non-labyrinthodont 
amphibians, which I have classed as lepospondyls in a broad 
use of that term, presents an evolutionary problem for which we 
have at present no solution. As Watson (1929) notes, amphibi- 
ans of this sort, already highly specialized, are present in the 
Lower Carboniferous, at a far earlier age than any labyrintho- 
donts except the ichthyostegalians. Neither in their spool-shaped 
holospondylous vertebrae nor in known skvill structures do they 
show the slightest indication of relationship to Labyrinthodontia. 
It is hoped that restudy of the oldest, Scottish, types will yield 
further light on their structure. But even so, we will still be con- 
fronted here with a major problem in early tetrapod evolution. 

BEFEKENCES CITED 

Baird, D. 

1957. Ehachitomous vertebrae in the loxommid amphibian Megalo- 
cephalus. Bull. Geol. Soc. Amer., 68: 1698. 
Credneb, H. 

1893. Die Stegocephalen und Saurier aus dem Eothliegenden des 
Plauen'schen Grundes bei Dresden. X. Theil. Zeitschr. deutsch. 
geol. Ges., 45: 639-704. 
Eaton, T. H., Jr. and P. L. Stewart 

1960. A new order of fishlike Amphibia from the Pennsylvanian of 
Kansas. Univ. Kansas Publ., Mus. Nat. Hist., 12: 217-240. 
Fbitsch, A. 

1889. Fauna der Gaskohle und der Kalksteine der Permformation 
Bohmens. Prague, 2: 1-114. 
Gregory, J. T. 

1950. Tetrapods of the Pennsylvanian nodules from Mazon Creek, 
Illinois. Amer. Jour. Sci., 248: 833-873. 



Plate I. A, the type specimen of PhuUdo(/aster piscif 
tion, "X. M. A.B noted in the text, dorsal neural spines, 
pletely preserved. 



omitted. B, attempted reatora- 
iiknown, uud the ribs are int^-oni- 



ROMEIi : LABYRINTHODONT PIIOLIDOGASTER 159 

Huxley, T. H. 

1862. On new labyrinthodonts from the Edinburgh coal-field. Quart. 
Jour. Geol. Soe. London, 18: 291-296. 
Jarvik, E. 

1952. On the fish-like tail in the ichthyostegid stegoccphalians. Mcddcl. 

om Gr0nland, 114 (12) : 1-90. 
1955. The oldest tetrapods and their foroninners. Sci. Monthly, 80: 
1-11-154. 
Panchen, a. L. and A. D. Walker 

1960. British Coal Measure labyrinthodont localities. Ann. Mag. Nat. 
Hist., (13) 3: 321-332. 
Parsons, T. S. and E. E. Williams 

1963. The relationships of the modern Amphibia: a re-evaluation. 
Quart. Eev. Biol., 38 (1) : 26-53. 

ROMER, A. S. 

1945. Vertebrate Paleontology. Chicago, 687 pp. 

1947. Review of the Labyrinthodontia. Bull. Mus. Comp. Zool., 99: 

1-368. 
1962. Vertebrate evolution. (Review.) Copeia, 1962 (1) : 223-227. 
Save-Soderbergh, G. 

1935. On the dermal bones of the head in labyrinthodont stegoccph- 
alians and primitive Reptilia. Meddel. om Gr0nland, 98 (3) : 

1-211. 
Spinar, Z. V. 

1952. Revise n'ekterych moravskych Diskosauriscidu. (Revision of 

some Moravian Discosauriscidae.) Rozpravy Ustredniho Ustavu 

Geologickeho, 25: 1-160. 
Steen, M. C. 

1934. The amphibian fauna from the South Joggins, Nova Scotia. 

Proe. Zool. Soc. London, 1934 (3): 465-504. 
1938. On the fossil Amphibia from the Gas Coal of Nyrany and other 

deposits in Czechoslovakia. Proc. Zool. Soc. London, (B) 108: 

205-283. 
Thomson, K. S. 

1962. Ehipidistian classification in relation to the origin of the tetra- 
pods. Breviora, Mus. Comp. Zool., 177: 1-12. 
Watson, D. M. S. 

1914. On a femur of reptilian type from the Lower Carboniferous of 

Scotland. Geol. Mag., (6) 1: 347-348. 
1926. Evolution and origin of the Amphibia. Philos. Trans. Roy. Soc. 

London, 214: 189-257. 
1929. The Carboniferous Amphibia of Scotland. Pal. Hungarica, 1: 

219-252. 
1940. The origin of frogs. Trans. Roy. Soc. Edinburgh, 60(1): 

195-231. 

(Received October 14, 1963) 



Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 
Vol. 131, No. 7 



EARLY EVOLUTION OF THE 
DISSOROPHID AMPHIBIANS 



By Robert L. Carroll 



With Two Plates 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

June 30, 1964 



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Phylogeny and Evolution of Crustacea. Proceedings of a confer- 
ence held at Cambridge, Mass., March 6-8, 1962. H. B. Whittington 
and W. D. I. Rolfe, editors. Cambridge, Mass., 192 pp., 80 figs., 1963. 
Cloth bound, $6.75. 

Fishes of the CTulf of Maine, by Henry B. Bigelow and William C. 
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Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 
Vol. 131, No. 7 



EAKI.Y EVOLUTIOX OF THE 
DISSOROPIIID AMPHIBIANS 



By KOBERT L. (^ARROLL 



With Two Plates 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

June, 19G4 



Hull. Mus. Cdiiiii. Zool.. ll,irv;iid I'uiv., 131(7 i : Hn-^.K), June, H)(U. 

No. 7 — Early Erithdioii of tin Dissorophid A)nphibiaiis^ 
By Robert L. Carroll- 

TABLE OP CONTENTS 

Tnti-odiu'tioii If).'? 

Morpholooy of Tersomius 10") 

Material Studied 1G6 

General Features of the Skull 168 

Separate Skull Elements 173 

Posteranial Skeleton 192 

Other Early Permian Dissorophids 192 

BroiUeUm 195 

Dissoroph us 202 

Brevidorsnm 210 

Aspidosaurus 214 

Conjunctio 218 

Interrelationships of the Permian Dissorophids 223 

Pennsylvanian Dissorophids 227 

Amphihamus lyelli 227 

Amphihamus calliprepes 241 

Amphihanius grondiceps 242 

Arl'anscrpcion arcuatum 244 

Interrelationships of the Pennsylvanian Dissorophids . . 244 

Relationships of the Dissorophidae among the Rhaehitomi 245 

Literature Cited 248 

INTRODUCTION 

The general phylogeny of the rhachitomous amphibians has 
been outlined in Romer's Review of the Labyrinthodontia 
(1947). The detailed evolutionary pattern of most of the fami- 
lies in this group, however, has yet to be determined. In many 
of the families the fossil record is still too incomplete to give 
a coherent picture. The deposits of the Lower Permian of Texas, 

1 Published by a grant from the Wptniore I'oIIps Fuud 

2 A draft of this paper w:is submirttMl in partial fnltillnifnt of thp requirenipiits 
for the degree of Doctor of I'hilosoph.v at Harvard University. 



164 BULLETIN- MUSEUM OF COMPARATIVE ZOOLOGY 

however, have accumulated over a sufficient len;_!;th of time to 
record adequately the histories of several groups ; one of these 
is the family Dissorophidae. This family has always attracted 
interest because its members possess a variety of patterns of 
dermal armor. The armor is in the form of single or double rows 
of plates resting above the vertebral column, in some genera 
forming a carapace resembling that of turtles. Dissorophids are 
further typified by the presence of a prominent pattern of 
cranial ridges and by conspicuous otic notches, closed posteriorly 
in some genera. All of the genera which have been described 
are relatively small, reaching a total length of a foot or so. 

Differences in the armor have made possible a much more 
detailed classification of this group than could be made from a 
study of other skeletal features; for this reason, the family has 
been divided into a larger number of genei-a than has any other 
family of rhachitomous amphibians. The classification of these 
genera has l)een sulxiect to a number of interpretations, most 
recently revicAved by DeMar (unpublished thesis. University of 
Chicago). 

Most of the genera Avhich liave lieen described come from 
the Clear Fork group, by v.liich time the various patterns of 
armor had become fully differentiated. In addition, there are 
a large number of specimens from the earlier, AVichita group. 
These specimens enable us to trace the early evolution of the 
armored dissorophids, and to determine their affiliation with 
several members of the family which have been described from 
the Pennsylvanian. 

Much of the material in the Harvard collection lielongs to 
the genus Tersomius, described by Case in 1910, and included as 
a primitive member of the Dissorophidae by Romer in 1947. 
Since this genus is so well represented, it will be described in 
detail as a basis for determining relationships among the other 
members of the family. This description forms the first part of 
this paper. In the second part, several new s])ecies of Permian 
dissorophids are described, together with a discussion of the 
general pattern of evolution within the family during that 
period. The Pennsjdvanian dissorophids are discussed in the last 
section. 

I wish to express my appreciation to Dr. Komer for suggest- 
ing this study and for offering many helpful suggestions 
throughout the course of the work. I would also like to thank 
Dr. Baird, at Princeton, who graciously allowed me to describe 
several specimens from Linton, Ohio, winch he had pr(>pared, 



CARROLL: DISSOKOIMlll) FAOLrTION 165 

and Dr. I)al(|iu'st at Midwestciii ( 'iiivci'sit y, Wichita Kails, 
Texas, for two specimens of TcrsoiiiiKs which he gave to the 
Museum of Comparative Zoology. For information coneerninp; 
the Clear Fork dissoro})lii(ls, and particularly their ai'mor, I 
am grateful to Dr. DeMar at the University of Chicago, and I 
wish to thank him foi- permission to summarize his findings. 
Yale Peabody Museum and tlie American Museum of Natural 
History have been very helpful in loaning material. I would 
also like to thaidc Professor Patterson and Dr. Williams for 
eritical reading of the manuscript. 

MORPHOLOGY OF TERS0MW8 
TeeSOMIUS Case 1910 

Tyjjc species. Tersomins texensis Case 1910. 

New diagnosis: Primitive dissorophid, lacking cranial orna- 
mentation. Otic notch not closed posteriorly. Frontal bone 
entering nmrgin of orbit. Each jaw has 45-50 teeth. Internarial 
bone present. 

Tersojiiits texensis Case 1910 
Figures 1-8 

Trrsomin.s ir.rcnsis Case, 1910, p. 180. 

Type: AMNIT 4719. Small skull with lower jaws. Left 
nasal region and the very back of the skull are missing and 
the palate is not exposed. Both orbits show remains of super- 
ficial eye plates. A second, fragmentary skull accompanies the 
type. It includes only the back portion of the left side, and 
apparently it was overlooked by Case in his original and subse- 
quent (1911) descriptions because of its small size. A tibia and 
humerus were collected with these skulls, but their size precludes 
association. 

Locality: South side of Little Wichita River, Archer County, 
Texas. 

Horizon: Belle Plains Formation. Wichita group. Lower Per- 
mian. - 

Dicujiiosis: Same as for genus. This is the only species known. 



1 .Muscuii) aliliicviatiiins : A.\L\n, AiiiiTicMii Miiscuin of Xaiural Ilistdrv ; 
BM(XH), r.ritish .Muscuiii (Natural History) : CXILM, Cliicajio Natural History 
Musi'Uiii : .MCZ, Muspuin of Coiniiara ti\r Zodlog-y : ICMr. riii\ crsii v of Cali- 
fornia Museum of I'alfoiitolouy : ISN'.AI, Ciiitfd Stati's National Museum: YI'.M, 
Yale Pealiody Museum. 

2 A eorrelatioii chart of rermian and Peiinsylvaniaii sf I'ati.urapliv follows tin- 
text. Correlation of Texas localities is based un Uonur, liJ.jti. 



166 bulletin: museum of comparative zoology 

Material Studied 

Since Case's original description, a great deal more material 
of this species has been discovered. Because there may be some 
variation from one formation to another, the material from 
each formation is listed separately. 
Belle Plains Formation 

MCZ 3351 and 3352. Two skulls with lower jaws, impregnated 
with ironstone and slightly distorted. Collected by Dalquest 
three miles east of Wichita Falls, Texas, E. Morrison survey, 
abstract no. 186. 
Putnam Formation, Archer City bone bed 

MCZ 1912 (Fig. 2). Skull and lower jaws, compressed longi- 
tudinally but otherwise undistorted, except for crushing of the 
rear portion of the braincase, occipital region and rear part of 
the parasphenoid. Collected by N. E. Wright, 1948, one mile 
southwest of Archer City, Texas ; prepared by S. J. Olsen. The 
description of the palate and skull roof is based on this specimen. 

MCZ 1415 (Fig. lA). Skull and lower jaws, complete except 
for surface of bones in front of orbits, with very little distortion. 
This skull is the basis for the description of the parasphenoid, 
occipital region and lower jaw. Collected by R. V. Witter and 
party, 1936. 

MCZ 1696. Jaw fragments collected by Witter and party, 
1936. 

MCZ 1694 (Fig. IB), a. Skull behind orbits, probably collected 
by Witter and party, 1936. Sectioned transversely at y^ milli- 
meter intervals employing the cellulose acetate peel technique. 
Basis of descriptions of otic and occipital regions. 

b. Back of left ramus of lower jaw and fragment of cheek 
region. Possibly associated with previous specimen. 

MCZ 3237. Skull in front of orbits with lower jaws in place. 
Collected with MCZ 1694. Removal of skull roof from this 
fragment allowed investigation of the dorsal surface of the 
palate. 

MCZ 3236. Skull in front of orbits, sectioned transversely at 
V2 millimeter intervals. Collected with MCZ 1694. Basis of nasal 
region description. 

MCZ 3235. Skull in front of orbits with lower jaws. Collected 
with MCZ 1694. Furnished portions of inner surface of lower 
jaws not seen in MCZ 1415 or 1694. 

MCZ 3234. Front of braincase ])etween orbits, sectioned trans- 
versely at VL' millimeter intervals. Found in either 1939 or 



CARKOl.L: DlSSOROIMIIl) KVOLUTIOX 



Ki? 



1941. Basis for (Icsci'ipl ion of the anterior I'c^ioii of the l)i'ain- 

case. 

Pueblo-Moraii boundary 

MCZ 11)11 (Fi^'. ID). Nearly complotc skull and lower jaws. 
Right side of skull turned under palate. Palate hadl}' distorted, 
left side of skull flattened, back of skull entirely gone. Colleeted 
by N. E. Wright, 1948. It was found north of the west fork 
of the Trinity River, section 1834, Texan Emigration and Land 
Co., Archer County, Texas. 




c 



D 



Fig. 1. Skulls of Tersomius. A, MCZ 1415; B, MCZ 1694; C, AMNH 
4719; D, MCZ 1911. X 1. 



16S BULLETIX: MFSEUM OF C0MPARATI\T: ZOOLOGY 

.J^A»7/,< ufiJisid for description: The tollowing desoription is 
based entirely on the Archer City specimens. BeciUise of the 
small size and incomplete nature of the tj-pe skull, it cannot 
be stated eatesrorically that it belongs to the same species as 
do the other specimens, although there is nothing to differentiate 
them in the material at hand. In contrast to Case's drawing, the 
prefrontal and postfrontal do not meet over the orbit. In gen- 
eral outline, the other Belle Plains specimens, collected by 
Dalquest. are indistiugnishable from those from Archer City. 
The matrix has been partially removed from them, but iroustone 
has destroyed the surface of the bone by infiltration, making 
detailed investigation impossible. Some features suggest that 
the geologically oldest skull, MCZ 1911, may differ slightly from 
the Archer City skulls; its peculiarities will be discussed in the 
second section. Neither this specimen nor the type is relied upon 
for this description. 

Because of the small size and fragile nature of the skulls. 
it was impossible to clean the inside surface of many of the 
cranial bones. For this reason it was necessary to section vir- 
tually the entire skull. Cellulose acetate peels were made from 
three large fragments of different animals. These peels were 
stained in a one per cent solution of aniline blue in water. This 
sttiined the bone a deep blue and the matrix remained its natural 
color. 

Unfortunately, not all of the specimens are of the same size 
or even relative dimensions. For this reason composite recon- 
structions of the under surface of the skull roof, the braincase. 
and the upper surface of the palate cannot correspond exactly 
with the dimensions of the surfaces taken from a whole specimen. 
Drawings were made from enlarged photographs of the whole 
specimens and from projections of the serial sections. 

General Featities of the Skull 

Evidently the tvpe specimen was an immature animal when 
it died, since its sutures are open. Although the type and 
acc-ompanying skull have almost identical dimensions, the latter 
has closed sutures. Presumably this indicates that these sutures 
close quite rapidly once the animal has reached a certain age. 
The estimated length of the type skull is about 60 per cent of 
that of MCZ 19121 Probably MCZ 1912 and the other Archer 
City specimens are mature since all fall within about 10 per 



f-ARKOLL: DFSHOROPHID EVOLUTION UifJ 

cent of a median sizf. The frafrments art' all of specimens slightly 
smaller than the complete skulls. 

Altlioujrh much of the information ref^ardin*^ the skull roof 
and palate is taken from MCZ 1912 (Fig. 2), a better idea of 
the relative dimensions is gained from MCZ 1415 fFig. lA;. 
The roof bones in front of the orbits are mostly destroyed, but 
the marginal Ijones and the lower jaws are intact, preservinir the 
outline of the skull. There appears to be very little distortion. 

The skull is small — only 64 mm from the tip of the snout 
to the end of the quadrates — and narrow, 47 mm at the widest 
point just behind the orbits. The highest point on the skull 
is at the rear of the skull table, 1') rnm above the base of the 
quadratojugal. The relative dimensions of height, width and 
length are quite similar to those of Eryops (Sawin, 1941), but 
the positions of the orbits, otic notch and external nares are 
not. The orljits are proportionately large, extending laterally to 
within a milliireter or two of the edge of the skull, and medially 
to the frontal bones. They are located slightly anterior to the 
middle of the skull. The external nares are 6 mm in diameter 
and are located near the margin of the .skull, less than 3 mm from 
its end. Their separation is equal to that of the orbits, about 
10 mm. The septomaxillae cover the posterior portion of the 
nares. Because of the cur^-ature of the skull, both the orbits and 
the external nares look out and forward. 

As in Eryops, the quadrates extend beyond the back of the 
skull roof. Viewed dor.sally, the skull table occupies most of 
the width of the skull, but is separated from the jaw suspen- 
sorium by a deep otic notch, incised 13 mm from the end of 
the tabular. The side margins of the skull form a continuous 
arc from the tip of the quadrate to the end of the snout. The 
skull table behind the orbits is almost flat. In front of the 
orbits the roof slopes in a convex cur\'e to the tip of the skull. 
In front of the otic notch the sides of the skull slope down at 
about a 45' angle. The posterior margin of the skull table is 
horizontal or slightly depressed above the foramen magnum. 
The posterior, unsculptured portion of the postparietals and 
tabulars slopes at about a 45^ angle toward the occipital con- 
dyles. The lateral posterior surface of the tabulars Ls sculptured 
and extends posteriori^' beyond the level of the sculptured por- 
tion of the postparietals. 

Specimen 1912 has large bony plates extending over the 
orbital cavity and projecting 6 mm above the skull roof. They 
are connected to the rear and medial portions of the orbital 



170 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

margin and evidently served to protect the eye. Apparently 
they were composed of one solid piece of bone since there is 
no consistency between the fracture patterns of the two eye 
plates. The plates are sculptured in the same manner as the 
remainder of the cranial bones. Remnants of eye plates were 
also seen in MCZ 3234, AMNH 4719, and MCZ 1911. The 
Pennsylvania!! dissorophid Amphibmnus had similar eye plates, 
both in the Linton species lyelli and the Mazon Creek species 
grandiceps. 

The pineal ope!!i!ig' is much further forward in Tersomms 
than in Eryops. The ratio of its distance from the foramen 
magnum to the total skull length is 1 :3.5, compared with a 
1:9.3 ratio in Eryops (Romer and Edinger, 1942). It is a milli- 
meter or so in diameter, and is located just behind a line join- 
ing the posterior margi!is of the orbits. 

With one exception, the roofing bones are those usually en- 
countered in an advanced rhachitomous form. The exception 
is an internarial bone located between the premaxillae and the 
nasals, i!i the same position as a bone in the ichthyostegids and 
some loxommids. 

No ridges, rims or hollows are present on the roof. The 
i!idividual bones are covered with a uniform fine pitting. This 
pitting does not extend into the otic !!otch. Presumably the 
place at w^hich the sculpturing stops !!iarks the position of the 
tympanic membrane. The occipital surface of the postparietals 
and tabulars also lacks sculpturing. There are no areas which 
could be considered as regions of secondary growth in the sense 
of Bystrow (1935). 

A ventral view of the skull (Fig. 4A) shows very large 
interpterygoid vacuities bordered laterally by !!arrow palatal 
bones. In addition to marginal teeth on the !iiaxillae and pre- 
maxillae, there are tusk-pairs on the ectopterygoid and palati!!e 
bones and two tusk-pairs on each vomer. Very fine denticles 
are present on all the bones except the parasphenoid. These are 
most conspicuous on the pterygoid. 

The parasphenoid and rear part of the pterygoids are best 
seen on MCZ 1415. The posterior plate of the parasphenoid is 
quite wide and underlies the back of the braincase. Basiptery- 
goid processes extend laterally behind the articulating rami of 
the pterygoids, one-fourth of the distance from the back of 
the skull, to form the basicranial articulation. Tlie cultrifo!-m 
process continues forward beneath the braincase to reach the 
vomers, dividing the interptei-ygoid vacuities medially. 



fWRROI.L : DISSOROPIIin EVOLUTION 



171 



The internal iiares arc proportionately rather large. Between 
them, just behind the front of the skull, lies a depression about 
the same size as an internal naris, termed the internarial pit, 
formed by the l)endin<i' of the vomers toward the skull roof. The 
posterior halves of the adduetor fenestrae are expanded medially 
for the temporal musculature. 

The margin of the palate is in a single plane. As viewed from 
below, the vomers are depressed medially for the reception of 
the parasphenoid as well as for the pit in front. The posterior 
portion of the ])terygoid rises above the remainder of the palate 
as it surrounds the median portion of the adductor fenestra. 
The parasphenoid is slightly depressed below the margin of 
the palate. The maxilla and premaxilla rise a millimeter or two 
above the lateral margin of the palatine bones, and overlap 
them to a variable extent. The articular surface of the quadrate 

TABLE 1 
Cranial Dimensions of Tersomius 







Type 
AMNH 

4719 


MCZ 1 

1912 


MCZ 

1415 


MCZ 
1694 


MCZ 
3234 


MCZ 
1911 


Length of cranium to 




34 


58 


64 


— 


— 


— 


extremity of quadrate 
















Length of cranium to 




32 


52 


58 


— 


— 


— 


foramen magnum 
Depth of skull in 




9 


14 


15 


13 


_ 


14 


front of otic notch 
















Greatest width of cranium 




36 


58 


47 


51 


— 


62 


between quadratojugals 
Least width of .skull table 




22 


33 


33 


32 


_ 


34 


dorsal to otic notch 
















Least width between orbits 




7 


11 


10 


11 


10 


14 


Transverse diameter of orbits 


11 


17 


14 


14 


— 


18 


Longitudinal diameter of orbits 


11 


15 


17 


— 


— 


16 


Distance from center of oi 


•bit 


19 


36 


38 


35 


— 


— 


to quadrate 
Distance from center of orbit to 


15 


24 


26 


_ 




28 


front of skull 
















Distance of pineal from Ijack of 


10 


18 


21 


25 


— 


— 


skull roof 
















Back of orbit to front of 


otic 


7 


13 


13 


12 


— 


11 


notch 

















1 Specimen compressed longitndin.ally. 

Dimensions of specimens are to the nearest miUinieter. 

Measurements taken from projections onto a flat surface. 



172 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

extends ventrally slightly beyond the margins of the pterygoid 
and quadratojugal. 

The upper surface of the palate (Fig. 5B) reflects, by and 
large, its lower surface. Above the vomers, however, are ridges 
projecting dorsally a millimeter or more, bordering the medial 
margins of the internal nares. These ridges extend back onto 
the palatines. Where the vomers meet above the internarial 
pit, they extend to the roof of the skull, separating the nasal 
sacs. 

The underside of the skull roof (Fig. 4 B) conforms to the 
contours of its external surface except in the region of the 
snout and front of the braincase. The depressions for cartilagi- 
nous nasal capsules are the most prominent feature. They ex- 
tend from the external nares posteriorly to the front of the 
orbits. Medially thej^ are bordered by a ridge on the nasal and 
prefrontal bones. Laterally they terminate at the juncture of 
the skull roof and palate. A passage for the nasolacrimal duct 
traverses the roof of the depression for the nasal sac. The 
passage is in the form of an open groove from the lip of the 
external naris to the middle of the depression, at which point it 
becomes enclosed in the bone of the lacrimal and continues as 
a raised tube to the front of the orbit, where it ])asses through 
three small holes in the edge of the lacrimal bone. 

Medial to the ridge on the nasal bone there is a groove wliieh 
runs from the nasal-prefrontal boundarj^ to the mid-point of 
the ridge. At this point the center of the skull between the 
nasal sac depressions is flat. The olfactory nerve may have 
crossed into the nasal sac where the medial groove terminates. 
Immediately lateral to this ridge, in fact partially enclosed in 
its lateral edge, is a groove or tube which probably helped to 
secure the margin of the cartilage of the nasal capsule. 

The occipital region (Fig. 5 A) was somewhat weathered in 
MCZ 1415, but the sectioned material serves to reconstruct the 
area. The double condyle is formed by the exoccipitals which 
reach dorsally on either side of the foramen magnum. The 
postparietals extend ventrally to border this opening. Below 
the foramen magnum is a slit above the medial juncture of the 
exoccipitals. This may have been filled with the otherwise miss- 
ing basioccipital and, as Sawin suggests in Eryops, the forward 
projection of the notochord. Lateral to the exoccipitals are the 
otic bones; paroccipital pr-ocesses from these bones extend la- 
terally and dorsally to the tal)ulars, bounding the posttemporal 



CARROLL: niSSOROPllID KVOLTTIOX 173 

fossae vent rjilly. Tlicsc opciiinu-s tire Ixifdrri'd dorsjilly by tlio 
bones of the skull i-oof. 

Tlio anterior jiorlioii of llic bi'aiiicase is x'isihlc hclwccn llio 
iiit('rpt('r\-^()i(l vacuities. Tlie splieiiel litiioid bones run llie leno'tli 
of tlie ])alate between the jiai'as])lienoi(l and the skull roof. Tlu' 
l)Osterior i)art of the braiiu-ase is mostly eoneealed by the para- 
sphenoid, except for tlie exoeeipitals and olie bones which are 
visible posteriorly. 

The mandible (Fiji'. 8) extends the full len«ith of the skull. 
It differs from that of Eryops in beino' much shallower in the 
ref?ion of the angular. Posteriorly the lower margin ascends 
gradually to the articular. Anteriorly the jaw tapers slightly, 
a feature accentuated in articulated specimens by the tendency 
of the jaws to be bent underneath the forepart of the skull. The 
coronoid process extends slightly higher above the tooth row in 
Tcrs/))iii)(s than in Erifops. Portj-seven teeth are carried on the 
dorsal surface of the dentary, and there are two more large 
teeth on the lower inside surface of that bone, lateral to the 
symphysis. There is no trace of coronoid teeth. On the medial 
surface of the jaw tluu-e is a large meckelian fossa below the 
coronoid process, a smaller inframeckelian fossa and a tiny man- 
dibular foramen. No trace of dental or mental foramina was seen. 
The lateral surface of the jaw is sculptured like the bones of 
the skull roof. One peculiarity of this genus is the presence of 
quite large fragments of bone lying between the rami (Fig. 3). 
They extend from the symphysis approximately halfway to the 
rear of the jaw and are found with even the small fragments 
of the snout. They have not been observed in any other dissoro- 
phids. These fragments are pitted in the same manner as are 
the lateral jaw surfaces and the roof of the skull. 

Separate Skull Elements 

Dermal hones of the skull roof: Due to the size and position of 
the orbits and otic notches, the skull of Tersomius differs mark- 
edly from such a "typical" rhachitome as Fry ops. Hence it 
is of value to describe the position and configuration of each 
element. 

The flat portion of the skull table is composed of six paired 
units : frontals, postfrontals, parietals, postparietals, supra- 
temporals and tabulars. The tabulars are small bones making 
up the posterolateral edge of the skull table. They extend back 
over the occipital region medially, where they are unsculptured. 



174 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 



ma 



A 
B 

C 

D 

E- 

F - 
G- 





pos 



B 



Fig. 2. Tersomius texensis. A, Dorsal view of skull, MCZ 1912 (Letters 
A-K refer to sections shown in Figure 6) ; B, Lateral view of skull, MCZ 
1912. X !%• List of abbreviations follows text. 



CAHHOLI, : DISSOKOI'Il ID KVOLrTIOX 175 

A'ciiti-ally they scud projections medially to the jiaroccipital 
processes of the otic bones. Medial to the tabiilars are the post- 
parictals. They extend twice as fai" forward on the skull roof 
as do the tabulars and, as is the case in other temnospondyls, 
are broadly in contact with the suprateninorals. T^nsciilptnred 
ventral flanges of the p()sti)arietals extend onto the occipital 
region on either side of the foramen magnum. Tn front of the 
tabulars are the supratemporals ; they are among the lai-gest 
skull units. The lateral margin of the supratemporal borders 
the squamosal above the otic notch. Posterior to the scpiamosal, 
the supratemporal itself borders the notch, at which point its 
margin is unsculptured. Anteriorly the supratemporal reaches 
the circumorbital bones. Medial to the supratemporals and 
anterior to the postparietals are the parietals, between which 
is the pineal foramen. This opening narrows from the lower to 
the upper surface of the bones. In front of the parietals are 
the large frontals. They extend to the margins of the oi-bits 
and support a portion of the bony eye plates. Anterior to 
the supratemporal bones, and lateral to the parietals and fi-on- 
tals, are the postfrontals which also border tlie oi-])its and sup- 
port part of the eye plates. 

Bordering the skull table are the bones of the lateral skull 
w'all. The s(iuamosal surrounds much of the otic notch. Its 
contact with the supratemporal occurs along the dorsal margin 
of the notch. The otic notch slopes ventrally from just beneath 
the skull roof toward the quadrate, and is floored by the squa- 
mosal, quadratojugal and pterygoid. The squamosal meets the 
pterygoid medially. The lateral margin of the s(iuamosal is in 
contact with the jugal and quadratojugal. The latter bone 
extends medially in the posterior portion of the notch floor to 
reach the pterygoid. The quadrate underlies these two bones 
at this point and extends only slightly further to the rear than 
they do. On the under surface of the skull roof the squamosal 
sends a large flange of bone parallel to the pterygoid along 
their juncture, beneath the anterior margin of the otic notch. 
This extension is not directly articulated to the pterygoid, but 
apparently helped strengthen the union of the two bones. Sawin 
suggests a cartilaginous connection from this flange, in Eryops, 
which would associate this structure with the palatoquadrate 
arch. 

In front of the otic notch are the circumorbital bones. The 
postorbital extends from the skull roof down over the cheek 
region. It shares with the frontal and postfrontal the task of 



176 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



supporting the palpebral cup. The jugals extend beneath the 
orbits, lateral to the postorbitals, to the lacrimals. The lateral 
margins of the jugal and lacrimal as well as the maxilla are 
partially obscured in dorsal view by the ventral inturning of 
the skull margin. The jugal does not extend toward the skull 
margin across the maxilla as it does in BroilieUus. The jugal 
and lacrimal extend medially and ventrally beneath the orl)it 




Fig. 3. Tersomius texensis. Palatal view of MCZ 1912 showing dermal 
ossifications between lower jaws. X 1- 



to reach the palate. Each sends a flange inward from the ex- 
ternally visible dorsal surface (best seen in transverse sections 
D and E, Fig. 6). Nothing of this nature occurs in Enjops, 
Avhose orbits are high above the palate. The lacrimal and pre- 
frontal continue this medial extension in front of the orbit. 
Three holes in the lacrimal bone open into the lacrimal duct. 
The lacrimal bone extends medially beneath the internal nares, 
providing a lateral floor for the nasal capsule. At this point 
it is below the surface of the medial margin of the internal 
nares. 

Between the lacrimal bone and the external naris is the septo- 
maxilla. This bone extends into the external naris halfway 
to its front margin. It articulates with the lacrimal, maxilla, 
premaxilla and vomer. The nasal, maxilla and iiremaxilla form 
the balance of the margin of the external naris. The internasal 



CARROLL: DISSOKol'lIll) lAOLrTION 177 

is a small (liaii'.oii(l-sliap(>(l hcnic Ix'twccii tlic nasals and pi-o- 
maxillao. Tt is locatod at tlic .jiiiicliirc of tli(^ vomers and tho 
skull roof. Tts jiosition is the same as that of the medial rostral 
fontanel in Pario.r^ia. the trematopsids, and th(> zati'aehyids. In 
MCZ .3285, the bone is missinpr, indicatino- the possibility of 
confusinp: a foramen with the mere loss of the bone. No particu- 
lar function is su^^ested for such a bone, but it miiiht be noted 
that the skull roof becomes superflnons where the vomers and 
premaxillae are in contact with the snrronndino: skull roof units. 

Th(> j)remaxillae and maxillae meet beneath the hind part of 
the external nares. Tosether, they bear a uniform assemblajxe 
of marpinal teeth, each tooth a simple peg, slantinp: sliphtly 
posteriorly. Room for 34 teeth in the maxilla and 13 in the pre- 
maxilla corresponds exactly with the number of teeth in the 
lower jaw. No particular ])attern of tooth succession was noted. 
The teeth are the same size throu<i'hout the jaw. Where they 
are complete they reach a len<2rth of approximately 2 nun. The 
remainder of the skull marpfin is composed of the (puidrato- 
jup'al, which meets the maxilla below the otic notcii, and the 
quadrate. 

Completing the skull roof are the nasal bones. They have one 
of the larpest surface exposures of the dorsal units. They extend 
from the frontals to the premaxillae ; laterally they reach the 
prefrontals and the lacrimals. Their ventral elaboration in con- 
nection with the nasal sacs has already been pointed out. 

Dermal hones of the palate: The palate is composed of the 
paired pterygoids, ectopterygoids, palatines and vomers, the 
median parasphenoid, and the medial extensions of the maxillae 
and premaxillae. The pterygoid is one of the most complicated 
bones in the skull. It consists of (1) a median basipterygoid re- 
gion which articulates with the parasphenoid and basisphenoid, 
(2) a quadrate ramus extending almost vertically toward the 
squamosal and supratemporal, and posteriorly to the quadrate, 
and (3) a palatine ramus extending forward to the ectopterygoid 
and palatine bones. 

The basipterygoid region forms a firm connection with the 
medial portion of the skull. A broad connection is made between 
a ventralh" directed flange of the parasphenoid and the ptery- 
goid. This is reinforced Ijy the basisphenoid which ()\(n-lai)s 
both bones at this point. Although it is clear that such an 
arrangement is intermediate between that observed in an animal 
with a movable palate and the type of sutural connection pi-esent 
in Eryops, it is doubtful that any movement was ])Ossible in 



178 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY 

pm- 



qj-^ 




Fig. 4. Tersomius texensis. A, Ventral view of palate, MCZ 1912, 
parasphenoid restored from MCZ 1415; B, Ventral view of skull roof with 
palate removed, composite drawing. X ^Vs- 



CARROLL: DISSOROl'IIID EVOLr'I'IO.V 179 

this palate. Tlic quadrate raimis extends behind tlie l)asiptei-y- 
jroid articulation. Its \-en1i-aI inai'<>'in is in the plane of the 
palate and i'orms the medial and posterior marjjins of the ad- 
ductor fenestra. Dorsally it extends toward the squamosal be- 
neath the otic notch, fonuinj^ the medial portion of the floor 
of this sti-ncture. The line of contact between the scjuamosal 
and ijteryjjoid slojies toward th(> (piadrate at the rear of the 
skull. Posteriorly, the pterygoid overlaps the quadrate. The 
palatal ramus extends forward medial to the ectopteryfjoid and 
palatine bones. On the specimen examined, it does jiot reach 
the vomers. Such a thin strip i)asses the eetopterygoid and pala- 
tine that one might suspect that it had originally been wider, 
although the specimen shows no definite sign of breakage or 
irregularity. No dorsal groove for a palatine cartilage was seen. 

The eetopterygoid, bearing one large tooth, forms the fi'ont 
margin of the adductor fenestra, and extends anteriorly to the 
palatine. Its lateral margin is covered ventrally by the maxilla. 
The palatine bears the same relation to the maxilla as does the 
eetopterygoid, and also carries one large tooth. It has a narrow 
dorsal ridge on the posterior margin of the internal naris. 

The vomers form the anterior region of the palate. Posteriorly 
they border the interpterygoid vacuities, and laterally the in- 
ternal nares. On the margin of the internal naris each bears a 
dorsal ridge continuous with that of the palatine and formed 
in the same manner, by an ineurling of the margin of the bone, 
best seen in Figure 6 C. The anteromedial portion of the 
vomers extends toward the skull roof. In front of the nasal 
sacs, the right and left vomers part to leave a narrow cleft in 
the palate which is covered ventrally by the premaxillae. Ap- 
parently this configuration of the vomers serves to support the 
medial portion of the nasal sacs. The internarial pit certainly 
is much larger than would be necessary to accommodate the 
parasymphysial tusks. Posteriorly the vomers rise to meet the 
parasphenoid and sphenethmoid. The vomers each bear two 
tusk-pairs. One is located at the anterior margin of the internal 
naris, in a comparable position to the single pair in Eryops. 
The other is located posteriorly and medially, halfway to the 
juncture of the two vomers. Both tusk-pairs are on the rim 
of the depression between the internal nares. 

The parasphenoid is divisible into an anterior cultriform 
process and a posterior plate bearing the basipterygoid articu- 
lation and underlying the posterior portion of the braincase. 
The cultriform process extends anteriorly to reach the vomers; 



180 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



for most of this distance it underlies the sphenethmoid. It 
extends across the ventral surface of the vomers approaching 
the posterior vomerine teeth. Behind the basicranial articula- 
tion the parasphenoid rises abruptly to a flat platform. Laterally 
it extends processes that surround the ventral portion of the 
otic region of the brain. Posteriorly the plate extends to the 
occipital region, lying just beneath the exoccipitals. Just behind 
the point of pterygoid articulation, the internal carotid arteries 




ma 




Fig. 5. Tersomius texensis. A, Posterior vicnv of skull; B, Dorsal view 
of palate; dashed line on premaxilla and nasal indicates point at which 
vomer reaches skull roof. X 1%- 



CARROLL : DISSOROI'I I ID KVOLT^TION 181 

cuter tlic parasphenoid. They are not readily apparent in an 
intact skull, but are revealed in sectioned material. Tn Eryops 
these arteries cross the lower surface of the parasphenoid and 
enter the skull anterior to the pterygoid articulation. The dorsal 
surface of the parasphenoid will be discussed with the braincase. 

In addition to carrying the marginal teeth and forming the 
margin of the skull roof, the maxillae and premaxillae extend 
ventrally across the margin of the ectopterygoid and palatine 
bones. The premaxillae do the same beneath the vomers, cover- 
ing completely the cleft where the vomers approach the skull 
roof. These are not simply contacts as in Eryops, but an over- 
lapping, so that removal of the marginal skull bones reveals 
bones of the palate above them, as if the palate were resting 
on a moulding. 

The palate of 2'ersomius differs from that of Eryops in the 
following features : 

(1) greater size of interpterygoid vacuities 

(2) strong contact between parasphenoid and vomers 

(3) failure of pterygoid to reach vomers 

(4) overlapping, rather than sutural connection betw^een 
parasphenoid and pterygoid 

(5) presence of tw^o vomerine tusk-pairs 

(6) passage of internal carotids through parasi)hen()i(l Ix'liiiid 
basicranial articulation 

(7) presence of internarial pit. 

The primary pala to quadrate arch: The primary palatoquad- 
rate arch is composed of the epipterygoid and the (juadrate, re- 
mains of the palatoquadrate cartilage. 

The quadrate is a solid bone, roughly tetrahedral in sliape, 
which articulates with the articular of the lower jaw. The base 
of the tetrahedron forms the articulating surface and has a 
concavity parallel Avith the long axis of the jaAV. The medial 
portion of the articulating surface extends further anteriorly 
than does the lateral. The dorsal anterior surface is covered 
by tlie squamosal, quadratojugal and pterj^goid. Only the 
posterior surface is exposed when the jaws are closed. The 
apex of the quadrate extends dorsally above the floor of the 
otic notch. There is an anterodorsal extension of the (juadrate 
beneath the pterygoid. 

The epipterygoid, visible only in the sectioned skull, MCZ 
1694, is divided into two parts, an ascending process arising just 
lateral to the basicranial articulation, and a prootic process, 



182 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



which is disarticulated from the remainder of the epipterygoid 
in this specimen. The ascending process is a stout rod of laminar 
bone articulating with the pterygoid at the juncture of the 
quadrate ramus and the basipterygoid region. It is 7 mm long 
and reaches within 1 or 2 mm of the skull roof lateral to the 
braincase (which is unossified in this area), slanting medially 
about 20° from the vertical. The rod ends abruptly anteriorly, 
but slopes slightly on its posterior margin. The base of the 
ascending process is about 21/2 mm thick. Posteriorly it articu- 
lates with the basisphenoid and the parasphenoid as well as 
with the pterygoid. 




:^x 



pf f. 







Fig. 6. Tersomius texensis. Transverse sections of skull ; positions indi- 
cated in Fig. 2 A. Sections AC from MCZ 3236, D-F from MCZ 3234, 
F-K from MCZ 1694; stippled areas are restored. X !• 



CARROLL: DISSOROIMIID FA'OLTTTTON 183 

Lateral to the braincase, in the region of the basicranial articu- 
lation, there are two bony rods -which lie just beneath the skull 
roof. These do not articulate with any of the otlier l)ones of the 
skull. The right rod is 3Vi> mm long, and its anterior end lies 
just posterior to the dorsal extremity of the ascending process 
of tlie epipterygoid. The left rod is dy? mm long and lies 
mostly anterior to the ascending process (Fig. 6, sections II 
and I). Although the bars are of unequal length, it is evident 
that they are paired structures. From the configuration of the 
epipterygoid in Dissorophus angusfus (Fig. 13 E) and in several 
genera discussed by Sushkin (1927), it is evident that these 
paired structures are the ])rootie processes of the epijiterygoids 
which have become disarticulated from the remainder of these 
bones. Judging from D. angustus, the left prootic process is 
probably nearly complete in this specimen of Tersoniius. The 
orientation of the bone in the two genera is probably similar, 
the anterior end articulating with the base of the ascending 
process, and the remainder of the bone extending dorsally at 
about a 45° angle from the base of the skull toward the anterior 
extremity of the otic capsule. Whether it articulated with the 
otic capsule in Tcrsomius is not known. In Tersomius the prootic 
process is roughly cylindrical anteriorly, but (piite flat and 
wide posteriorly. Unlike the ascending process, the prootic 
process is composed of very porous bone, giving the appear- 
ance of being hollow at its anterior extremity. 

There is no real quadrate ramus of the epipterygoid. Because 
of the deep otic notch, the quadrate ramus of the pterygoid ex- 
tends far anteriorly and so appears lateral to the ascending 
process of the epipterygoid for a short distance, effectively sepa- 
rating the quadrate from the epipterygoid. 

The great extent of the prootic process of the epipterygoid, 
and the lack of persistent contact between the epipterygoid and 
pterygoid differentiate this genus sharply from Enjops. 

The hraincase (based primarily on sectioned skull MCZ 1694) : 
In general, the braincase (Fig. 7) of Tersomius is similar to that 
of other labyrinthodonts in having two main areas of endo- 
chondral ossification, the anterior sphenethmoid and the pos- 
terior otico-occipital. Dorsally and ventrally the endochondral 
bone is covered by dermal ossifications of the skull roof and 
palate. The lateral walls in the region of the basicranial articu- 
lation are less ossified than in Eryops, but otherwise most fea- 
tures are similar to those of that eenus. 



184 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

The exoceipitals form the occipital condyles and the side 
walls of the posterior portion of the braincase. They are fused 
ventrally, except for the posterior 2 mm. There is no bony 
basioeeipital, but a g-roove dorsal to the point of fusion of the 
exoceipitals was evidently occupied by the cartilaginous pre- 
cursor of this bone. Whether the basioeeipital cartilage con- 
tinued to the surface of the condyle cannot be determined from 
the shape of the exoceipitals, but the structure of the atlas 
suggests that there was no medial area of articulation with the 
occipital condyle, and hence that this structure was double. The 
dorsal margin of the foramen magnum is not preserved in the 
sectioned material, so it is not possible to determine whether the 
exoceipitals joined one another dorsally, as in Eryops, or whether 
there was a separate supraoccipital. Dorsally this area is cov- 
ered by the postparietals which extend lappets on either side 
of the foramen magnum over the posterior surface of the 
exoceipitals. 

The exoccipital extends forward from the condyle approxi- 
mately 7 mm ventrally, indented al)ove by the basioeeipital 
trough. Dorsolaterally the exoccipital terminates 214 mm an- 
terior to the tip of the condyle. Just anterior to the condyle 
are three or four foramina. There are two distinct ventral 
foramina, one ahead of the other, just above the basioeeipital 
groove. The posterior one opens posterodorsally, and the an- 
terior one posteroventrally. From their position it is evident 
that they were passages for branches of the Xllth nerve. 
Dorsal to these openings, there appear openings in each of two 
successive half -millimeter sections, extending directly laterally. 
It is not possible to tell whether these represent two separate 
openings, or the extremities of one large fenestra. It (or they) 
presumably provided passage for a further branch or branches 
of the hypoglossal nerve. Anterior and dorsal to these openings 
is a small foramen, perhaps for a small vein. 

The otic region is preserved only on the right side of the 
specimen sectioned. It does not appear to be divided into sepa- 
rate opisthotic and prootic ossifications. The ventral anterior 
portion of the otic capsule is either not ossified, or simply miss- 
ing in this specimen. Since the anterior vertical semicircular 
canal is partially enclosed in bone, and at least the dorsal margin 
of the fenestra ovalis is present, the missing portion of the otic 
ossification cannot be equated with the entire prootie. This re- 
gion of the braincase is also poorly ossified in other genera of 
dissorophids (DeMar, unpublished thesis). The otic ossification 



CARROLL: DISSOROIMIID EVOLT^TIOX 185 

is iHoi'c lat(>i'ally dircctrd lliaii in Enjop^, and is not in contact 
with the exoccipital cxci^pt at its postci-odorsal margin. Laterally 
and ventralh' there is a cleft between the exoccipital and otic 
bones that accommodated the vagus nerve, as well as the IXth 
and Xlth nerves and the jugular vein. Beginning anteriorly 
about 4I/2 mm in front of the end of the condyles, this passage 
extends posteriorly to ojieii 1)eliind the otic capsule. This cleft 
was certainly closed vent rally with cartilage. 

The posterior wall of the otic capsule extends dorsally and 
laterally as the paroccipital process to meet the tabular bone. 
This process forms the ventral margin of the posttemporal fossa, 
dorsall.y and laterally bordered by the tabular, and medially by 
the postparietal. This opening continues anteriorly for 4 mm 
before entering the cranio-quadrate passage lateral to the brain- 
ease. There is little variation in the dimensions of the post- 
temporal foramen throughout its length. The fenestra ovalis 
is located a millimeter or so in front of the rear wall of the 
otic capsule, beneath the paroccipital process. It is about a 
millimeter in diameter. Anteriorly it is bordered by bone only 
dorsally. There is also a foramen in the medial wall of the 
otic capsule, just anterior to its rear border. Perhaps, as in 
some lizards (Gaupp, 1900), this opening was occupied by a 
perilymphatic duct connected with the passage for the vagus 
nerve. No such opening has been observed in Eryops. The 
dorsal medial wall of the otic capsule turns medially anterior 
to the fenestra ovalis and forms the lateral wall of the brain- 
case. The passage for the Vlllth nerve w^as somewhere anterior 
to this point, but its exact location cannot be determined. Dor- 
sally the otic bones almost meet one another in this area. IIow 
much of the dorsal covering of the Ijraincase was formed by 
the otic bones cannot be determined since the upper surface 
of the specimen sectioned is missing in this area. 

Only the posterior and dorsal portions of the inner surface 
of the otic capsule are preserved. Dorsal to the fenestra ovalis 
there is a groove in the roof of the capsule for the posterior 
vertical semicircular canal. The groove extends anteriorly and 
iiu'dially. In front of the fenestra ovalis this groove continues, 
turning somewhat laterally", and becomes enclosed ventrally by 
bone. This is evidently- the position of the anterior vertical semi- 
circular canal. Anterior to this point, only that portion of the 
otic capsule beneath the i)osttemporal foramen is i)reserved. 
There is no direct evidence for the horizontal semicircular canal. 



186 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

A ventral pocket medial to the fenestra ovalis wan evidently 
occupied by the sacculus and utriculus. 

The lateral walls of the braincase are unossified between the 
otic bone and the sphenethmoid. Nerves IV through VII pre- 
sumably left the brain through this gap. Anterior to the termina- 
tion of the exoccipital, the base of the braincase is formed by 
the parasphenoid, presumably covered by a portion of the carti- 
laginous basioccipital. 

The posterior margin of the basisphenoid is 3 mm anterior to 
the end of the exoccipital. The basisphenoid has a groove which 
corresponds with the basioccipital groove in the exoccipital. This 
may mark the anterior extension of a persistent notochord. The 
basisphenoid extends as a stout bar across the parasphenoid, 
exceeding this bone in width anteriorly. The lateral edges are 
thickened where it is in contact with the pterygoids. The anterior 
medial portion of the bone is pierced to a depth of over a milli- 
meter by paired recesses for the rectus eye muscles, much as in 
Eryops. Two small foramina lead from the internal carotids 
into the recesses in the basisphenoid. A third foramen leads 
into a canal which traverses the basisphenoid between the re- 
cesses, continuing anteriorly through a small dorsal projection 
of the parasphenoid, and posteriorly extending into or above 
the groove for the notochord. It may have contained a vein 
which carried the blood from the eye muscles, although no 
passages were seen between the eye muscle recesses and the 
vessel in the sections examined. The blood probably flowed 
into the hypophysial vein, although the exact location of 
this vessel cannot be determined due to lack of ossification in 
this area. 

Anterior to the basisphenoid, the parasphenoid forms the 
bony base of the cerebral cavity. Up to this point the para- 
sphenoid has always been separated from the cranial cavity by 
either bone or cartilage and so was not described in detail. 
Before discussing this area, we should return to the construction 
of the parasphenoid at the back of the skull. This bone is first 
encountered beneath the exoccipitals, level with the posterior 
wall of the otic capsules. It widens rapidly to surround the 
ventral margins of the otic bones and extends dorsally around 
their lateral walls. The dorsal margin curves ventrally beneath 
the fenestra ovalis. Whether there was attachment to the stapes 
cannot be determined since that bone is not present in any of the 
specimens examined. Dissorophns multicinctus, from the Clear 
Fork, has the parasphenoid partially fused to the base of the 



CARROLL : DISSOROPIIID EVOLITTION 



187 



stapes. This situation also jji-cvails in Eryops and Edops. 
AntiM'ior to tho fenesti-a ovalis, the i)arasj)h('iioid is in contact 
with the portion of tho otic capsule lying beneath the post- 
temporal foramen. It is difficult to differentiate the two bones 
in this area. It is j)robabIe that some portions of the bone 
labeled parasphenoid in Figui"e 5 B are actually part of the 
otic capsule. 

The dorsal extension of the parasphenoid ends just posterior 
to the basicranial articulation. Here the parasphenoid extends 








bo&nch 



icf' set ps 




Fig. 7. Tersomius texctisis. Braincase. A, Median sagittal si't-tion 
(double hatching indicates restored portions) ; B, Dorsal view of lioii- 
zontally sectioned braincase, plane of section indicated in A. X -• Com- 
posite drawings. 



188 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

laterally, in contact -with the basipterygoid ramus of the ptery- 
goid, almost to the quadrate ramus. The parasjohenoid curves 
ventrally across the area of the basicranial articulation, taper- 
ing in width anteriorly. The internal carotid arteries enter 
the parasphenoid just posterior to the articulation. At the point 
where they enter, they are separated by 6 or 7 mm. They pro- 
ceed medially forward, immediately beneath the basisphenoid. 
The canals for left and right internal carotids join one milli- 
meter beyond the end of the basisphenoid. At their juncture, 
a small bone is present in the canal, separating it into dorsal 
and ventral channels ; within a millimeter, however, this bone 
is gone and the canal opens dorsally. 

Throughout the area of the basicranial articulation the para- 
sphenoid is considerably thicker than it is posteriorly. This 
thickened area continues anteriorly up to the point where the 
carotid arteries pass out of the bone. The parasphenoid dimin- 
ishes in width to about 3 mm anterior to the basicranial articula- 
tion. Just anterior to the basisphenoid, the parasphenoid has a 
small dorsal extension pierced by the foramen that runs between 
the recesses for the eye muscles in the basisphenoid. Anterior 
to this dorsal extension the parasphenoid is oval in cross section 
for 2 mm, at which point the internal carotids leave dorsally. 
The pituitary was apparently housed just anterior to the basi- 
sphenoid, although there is no evidence of a recess for this 
organ in either the basisphenoid or the parasphenoid. Vessels 
extend dorsally from the internal carotids in this region; pre- 
sumably these vessels passed dorsally into a cartilaginous sella 
turcica. Anterior to this point a trough (a millimeter deep and 
iy2 mm wide) is formed in the parasphenoid. Anteriorly the 
walls of the trough are reduced and the parasphenoid continues 
forward, shaped as a bar, dorsally concave. Within 2 or 3 mm 
of reaching the vomers the dorsal depression vanishes. 

In front of the pituitary, the braincase is again walled 
laterally by bone. Arising from the dorsolateral margins of 
the parasphenoid and extending anteriorly to the vomers are the 
paired sphenethmoid bones. In cross section the sphenethmoids 
form a V-shaped trough. As viewed laterally, each bone is in 
the shape of a trapezoid, whose top approaches the skull roof. 
Cartilage probably joined the sphenethmoid to the basisphenoid, 
with openings for the eye muscles and various cranial nerves. 

Just ahead of its posterior extremity, the sphenethmoid is 
pierced by two pairs of foramina. The anterior openings could 
have accommodated the optic nerve and probably the ophthalmic 



CARKOI.I. : DISSOROI'ITID EVOLUTION' 189 

artery, since the opciiiiifi's are qnitc larii'c. Tlic postorior pair 
presniiiahly allowed passajje for the oculomotor nerve. 

Tlie splieiietlnuoids are separated veiitrally by the para- 
splieiioid for a distance of 6 ram, heyond which they are in 
contact nntil they eome within 2 or 3 mm of tlie vomers, where 
they ai-e a<i'ain separated by the parasphenoid. Where the 
sphenethmoids approach the slcnll roof, they are separated from 
it by a narrow space, evidently filled with cartilage in life. It 
appears that this cartilapre continued medially joininfj: the 
sphenethmoids dorsal to the cranial cavity. This cartila<ii:inous 
strip made contact with the postfrontals and frontals. The 
frontal bone bears a rid<;e jnst lateral to the brainease, which it 
probably served to strenjjthen. This rid<i'e continnes on beyond 
the end of the sphenethmoid almost to the ridp-es surronndinp 
the nasal eapsnle. 

In cross section it can be seen that the sphenethmoids are 
composed of external and internal sheets of ver^^ thin bone, 
joined by innnerons stmts. The inner layer of bone g'ives a more 
rounded cross section than the external layer, especially toward 
the anterior end of the brainease. There is no trace of any 
inedial division such as is present in Trcmatops. 

The sphenethmoid is very different from that of Eryops. In 
Tcrsomiux the bone is obviously paired, thin and fragfile, and 
with no median partitions or grooves to separate the olfactory 
nerves and associated vessels. In Tersomius the parasphenoid 
helps to support the sphenethmoid, while in Eryops it is a mere 
accessory to the sphenethmoid, which is the most massive element 
in the skull. 

The most obvious distinction between the braincases of Eryops 
and Tersomius is the anterior position of the pineal opening, in 
the latter, relative to the opening for the optic nerve and the 
position of the pituitary. The floor of the brainease is much 
thinner in Tersomius than it is in Eryops or Edops. 

Running near the dorsal extension of the parasphenoid for 
some distance, in MCZ 1694, are two ossified tubes. These 
passages appear first just in front of the anterior termination 
of the right exoccipital, above the disarticulated prootic process. 
They continue anteriorly, moving medially to lie between these 
processes. They can be traced anteriorly as far as the confluence 
of the carotids and are most clearly visible in the area of the 
basisphenoid. The more lateral of the two is about half a milli- 
meter in diameter and almost solid, with a hole less than an 
eighth of a millimeter in diameter through the middle. The 



190 



BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 



medial vessel is somewhat larger and has very thin walls. The 
pair are probably the vena capita lateralis (medially) and the 
supraorbital branch of the stapedial artery (laterally). 

Mandible: Each lower jaw is composed of nine dermal bones 
and the articular. On the lateral surface are exposed the angu- 
lar, surangular, dentary, coronoid, splenial, postsplenial and 
articular. The largest bone is the dentary, extending from the 
symphysis to the coronoid process. A narrow strip of splenial 
and an even smaller area of the postsplenial separate it from 




Fig. 8. Tersomius texensis. Lower jaw. A, Lateral view; B, Mediai 

view; C, Dorsal view; D, Ventral view; E, Posterior view. X 1- F, 

Transverse sections of jaw at positions indicated in A. X -• Composite 
drawings. 



fARROLL : niSSOROIMIID KVOH'TIOX 191 

the ventral margin f)f the jaw. Posterior and ventral to the 
(IfMitary tlie inarp:iii of the jaw is formed liy the aii^ndar. Dorsal 
to the angular is the sui'aiifrnlai'. foriinii<;' most of tlie dorsal 
mai'^in of the coi-oiioid pi-ocess. TIic suranji'ulai" is not senlp- 
turcd where it is covered by the skull roof. A tiny portion 
of tlie articular is visible above the ])oster'ior extremity of the 
surau<>'ular. Tlie coronoid lies auter-ior to tlu^ suran<i'uhir and 
dorsal to the posterior portion of the dciitai'N-, behind the teeth. 
It forms the anterior portion of the eoi'onoid process. 

Medially, the iinier surface of the l)ones discussed on the 
outside of the jaw can be seen, as well as the preeoronoid, inter- 
coronoid, and the prearticular. The dentar}^ is deeply grooved 
on the dorsal margin, and it is from the lateral edge of this 
groove that the teeth grow. The lateral ridge covers the base 
of the teeth to a much greater extent than it does in Erijops. 
The teeth are roughly uniform in size except for those at the 
very l)ack of the jaw^, which are somewhat smaller. The majority 
of the teeth reach a length of 2 mm, as do those in the upper 
jaw. There is room for 47 teeth. The pattern of replacement 
is not clear. The anterior portion of the medial surface of the 
dentary forms the dorsal one-half or two-thirds of the symphysis 
and is thickened to support 2 additional teeth, which extend 
posteriorly and dorsally. These teeth enter the anterior part 
of tlie internarial pit. 

The three coronoids form a median rim to the groove in the 
dentary. The precoronoid is very narrow at the symphysis and 
is recessed beneath the dentary and the splenial. It continues 
posteriorly for about one-third the length of the jaw and then 
gives way to the intercoronoid. Behind this is the coronoid 
which not only forms the anterior portion of the coronoid process 
but also borders the back of the tooth row. This bone is deflected 
outward in the anterior portion of the coronoid process. Ventral 
to the coronoids are the splenial, anteriorly, the postsplenial, 
pierced by the mandibular foramen, and the prearticular. The 
splenials have a considerably larger exposure on the medial 
surface than they do on the lateral. The prearticular is the 
largest bone exposed medially. Together with a portion of the 
angular it forms the medial wall of the meckelian fossa. Between 
these bones, below and anterior to the meckelian fossa, is the 
inframeckelian fossa. There is some ditference in the propor- 
tions of these bones and their counterparts in Eryops. The 
splenial is longer in Tersomius, while the postsplenial is con- 
siderably shorter. The prearticular is also shorter, failing to 



192 BULLETIN: MUSEUM OP COMPARATIVE ZOOLOGY 

reach the precoronoid. An even smaller portion of the splenial 
and postsplenial is visible on the external surface than in Eryops. 

The articular can be adequately viewed only from above. 
It is supported by the surangular, angular and prearticular. 
The articular surface is quite flat but irregular. As in the quad- 
rate, the articulating surface is larger medially than laterally. 
The bone is quite thick anteriorly where it borders the meckelian 
fossa. 

The meckelian canal continues the entire length of the jaw, 
and can be seen at the symphysis ; it ends before reaching the 
symphysis in Eryops. Dorsal to the meckelian canal is a small 
canal in the dentary running most of the length of the jaw. 
Such a canal was not noted in Eryops. Failure to find the dental 
and mental foramina in Tersomius is attributed to the small 
size of the specimens. 

POSTCRANIAL SKELETON 

The only posteranial material associated with Tcrsomins con- 
sists of fragmentary atlases, Nos. MCZ 1415, 1694 and 1912. 
A tibia and humerus collected with AMNH 4719 cannot belong 
with the skull because of their size. No armor has been found 
with seven complete or nearly complete skulls and numerous 
skull fragments. The remainder of the known Permian dis- 
sorophids have armor associated with the cranial material. This 
seems to suggest that the lack of armor is real and not an arti- 
fact. (In the genus Dissorophus, the presence of a large dorsal 
shield appears to be the factor responsible for the preservation 
of well articulated skeletal parts since most of the limbs are 
laid out directly under the shield.) 

OTHER EARLY PERMIAN DISSOROPHIDS 

Several additional genera of dissorophids have been descril)ed 
from the Lower Permian of Texas and New Mexico : Broil ielJus, 
Dissorophus, Alegeinosaurus, Cacops and Aspidosaurus. DeMar 
has recently reviewed these genera, known primarily from the 
Clear Fork group, and classified them on the basis of their armor. 
His description of the armor is summarized here to facilitate 
comparison with the armor of the species from the Wichita 
group, which are described below. 

Broiliellus has a single plate of wide armor per segment ; the 
center of each plate is located between adjacent neural arches. 



CARHOIJ;: DISSOKOI'lllI) lAOIJTlON 193 

Fr('(iu('iitly, a voiitral flaiififo projects from the center of the 
armor plates and eitliri- extends between adjacent neural arches, 
or enters slits in the ends of the neural spines. There are 13 or 
14 su(']i jilates of uniform size, which are ornamented like the 
bones of the skull roof. Each plate is in contact with the one fore 
and aft, but adjacent plates are neither fused nor imbricated. 
Broilicllns texensis is known primarily from the Clyde Forma- 
tion ; a second species, from the Arroyo Formal ion. is being 
described b3' DeMar. 

Dissorophns has two layers of wide armor plating-; the internal 
layer is similar to that of Broiliellus except that it extends for 
seven or eight more segments. Dorsal to and alternating with 
this armor is a second set of plates of approximately the same 
size and shape. The internal shields are not ornamented where 
they are covered by the external series. Several anterior seg- 
ments are covered by a continuous sheet of armor, composed of 
shields from both series in an irregular manner. None of the 
shields is fused to the neural spines. 

Alegeinosaurus and Cacops ditfer from Broiliellus and Dis- 
sorophus in having a narrow internal series of armor which 
appears to be an outgrowth of the neural spines, and a narrow 
external series. The two series are related to each other in 
the same manner as are the external and internal series in 
Dissorophns. There are 15 vertebrae so armored in Cacops ; the 
number is not known in Alegeinosaurus. 

More variation is encountered in Aspidosaurus than in the 
other genera. The type species, A. chiton, has neural spines 
expanded into narrow sculptured shields, some, but not all, of 
which overlap the shields of the preceding vertebrae. There is 
only one layer of armor, and the number of vertebrae which 
are covered is not known. A. glascocki has massive armor of a 
similar nature to that of A. chiton, but apparently not imbri- 
cated. A. apicalis and A. crucifer are known only from isolated 
armored neural spines. The latter species gives the impression 
of possessing an external layer of armor (although none has 
been found) since the anterior and posterior margins of the 
plates are not sculptured. A number of very large armored 
neural spines, several of which are in the collection of the 
Museum of Comparative Zoology (Plate 1), have been associated 
with this genus, but these spines are much larger than are the 
entire vertebrae of any other dissorophids. 

DeMar classified these genera in two subfamilies based on 
differences in the armor. Dissorophns and Broilicllns, with broad 



194 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



1— I t^ CO 



■S.MtSJ 



"^2 







1 -rh o ira I— 1 fo I— 1 05 


5SN ! 


1 Cl lO ^ Cl rH (M CO 




o; •^ 





" § lis 



.5^»'-IOOOO«Dt-OitOCOOOO<35lCOi 

'S'OiotO'Oi— llOC0i-(i— li-ICOCvli-l 



-! 05 



be 



TO p^ TO H O) _H 






be 



• s I £ t5 S ^ 3 .t5 - S -^ - o 






Ji CU O) QJ q_| p - 

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flflajojcjrtcjC 



0) fc- in (P O) fc. O --^ •'-'•'-< K 



c'AKRoi.r. : DissoKoi'iiii) i:\()Lr'r!().\ 195 

ariiiof plates not fused to the iieiii-al s])iiips, werp placed in 
the subfamily Dissoi-ophiiiae. Cacops, AJ(()einomurus and Aspi- 
closaurus;, witli narrow armor fused to the neural spines, were 
placed in the Aspidosaurinae. DeMar felt that the iiatui-e of 
the armor prohaI)ly indicated that it had developed separately 
in the two y'roups. Se])aration of the two sul)families is also 
su<>'<jested by the natui-e of the sacral ribs; thei-e is a sinule pair 
in DissoropJius, but Cacops has two pairs. The remainder of 
the postcranial skeleton is not sufficiently known for com]iai-ison 
throuii'hout the family. All of the armored u'cnera have a 
pattiM-n of rido-es surrounding the orbits and bordei-in^- the skull 
table. This pattei-n diifers somewhat in the two groups, but 
the differences are not as diagnostic as those observed in the 
armor. Both Cacops and Dissorophus have the otic notch closed 
posteriorly, while it is open in the remaining genera. 

DeMar described two new genera, but neither is well enough 
knowai to place in either subfamily. The same is true of the 
Russian genus Zygosaurus. 

BlJOILTELLUS Williston 1!)14 

Broiliellus brevis^ sp. n. 

Figures 9, 10 and 11 

Type: MCZ 1424, complete skull with lower jaws; partial 
postcranial skeleton including 12 vertebrae, 9 armor plates, 9 
ribs, left and right cleithra and scapulae, fragments of tiie 
clavicles and the left humerus. 

Referred specimen: MCZ 3272, partial skull and fragments 
of both lower jaws. An almost complete pelvic girdle, a pair of 
sacral ribs and the ])roximal portion of the left femur are possi- 
bly associated. 

Locality: Both specimens were collected from the Archer City 
bone bed, one mile southwest of Archer City, Archer Co., Texas. 

Horizon: Putnam Formation, \Yichita group. Lower Permian. 

Collectors: MCZ 1424, collected by Witter, 1936; MCZ 3272, 
collected by Romer, 1961. 

Diagnosis: Dissorophid possessing a single layer of narrow 
armor plates, not fused to vertebrae. Skull similar to that of 
Broiliellus texensis, except for shorter skull table posterior to 
orbits. Open otic notch. 



1 Urcris: from the Latin nieauiiig short in space or time, in reference to the 
shortness of the armor plates. 



196 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



Description: The skull of Broiliellus hrevis (Fig. 9) differs 
from that of B. texensis in having a shorter skull table behind 
the orbits, and shallower otic notches. These features are shared 
with Tcrsomius and the Pennsylvanian dissorophids. The tabu- 
lars descend slightly toward the quadrates, but do not close 
the notches behind. The ornamentations on the skull roof are 





pm 



Fig. 9. Broiliellus hrevis. MCZ 1424. A, Dorsal view of skull; B, Lateral 
view of skull. X !• 



CARROLL: nissoRoriiin evolution 197 

ill the same positions as those in Ji. te.>rnsi<i, l)ut are slip:htly 
less prononneed. Tlie jn^al, as noted in B. tcxrnsis by Williston, 
has a projection from its ventral surface, in this case extending 
across the maxilla and quadratojugal to the h'vel of the tooth 
row. There are prominent ossifications in the orbits, essentially 
the same as in B. tcxensis, and presnmal)ly liaving the same 
configuration in life as the ossifications in Tcrsomius. 

Between the type and the referred si)ecimen, ahnost the 
entire palate can be determined (Fig. 10 A). As in B. texensis, 
there are flanges on tlie posterior extremity of the parasphenoid 
for muscle attachments. All the paired bones of the palate are 
covered by a thick shagreen of tiny teeth. The anterior portion 
of the vomers ascends to the skull roof, as in Tersomius. A 
single fang was seen projecting from each vomer and palatine 
bone, but the ectopterygoid tooth and, in fact, the major portion 
of the ectopterygoid bone are covered by the lower jaws in the 
type, while this region is missing in the referred specimen. The 
internal nares are somewhat longer and considerably narrower 
than they are in Tersomius or Cacops. The internal nares 
of a specimen of Broiliellus texensis from the Belle Plains, MCZ 
1747, are also long and narrow. In the referred specimen of 
B. Irevis, the dorsal surface of the palate is visible and discloses 
a dorsally projecting rim on the vomer and palatine along the 
medial margin of the internal nares, similar to that observed in 
Tersomius. The ventral projection of the jugal is visible in 
palatal view. There is room for 39 teeth in the maxilla and 13 
in the premaxilla; each tooth is a simple pointed peg, reaching 
a length of one or two mm. The right stapes is present, extend- 
ing from the anterior corner of the otic notch to the lateral 
margin of the parasphenoid plate. None of the braincase is 
visible. 

The jaws are clearly exposed in ventral and lateral views. 
They are distinctive in two respects. The lateral surface of 
the angular is very deeply sculptured, particularly in the type, 
in contrast to the dentary. Ventrally the angular has a pro- 
jection considerably beyond the remaining surface of the bone. 
The jaws of other species of Broiliellus have not lieen described 
in any detail, so comparison is not possible. 

The block containing the skeletal material (Fig. 10 B) was 
in contact with the skull of the type and the fragments were 
more or less in their natural position. The armor plates are 
somewhat disturbed and lie to one side of the vertebral column. 
The armor differs from that of Broiliellus texensis in being 



198 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

very narrow; the widest segment is only about 12 mm across, 
compared with a cranial width of 54 mm. In B. fexensis, the 
armor is over half the width of the skull. The structure of 
the armor, however, is essentially similar to that species — a 
single, un fused, transversely elongated segment for each verte- 
bra. The plates average about 3 mm in length, although there 
is some irregularity. They narrow from 12 to 8 mm in width 
in the first six preserved shields. The most anterior shield is 
rounded in front, but this may be an artifact of preservation 
and does not necessarily indicate an anteriormost position in 
life. The plates do not appear to overlap, but are in close 
contact. Only one shield, the 8th in the series, is visible from 
below; it does not appear to bear a ventral flange. If the 
shields are in place along the length of the column, there is 
room for 4 more plates in front, making a total of 13. Whether 
there were more posteriorly cannot be determined. There are 
13 or 14 armor plates in B. fexensis. 

Approximately 12 vertebrae are preserved in the block. The 
anterior 3 shoAV only the neural arch, truncated, and the right 
transverse process. In related genera, the transverse processes 
of the first 2 vertebrae are modified ; apparently these vertebrae 
are missing in this specimen, since the first vertebra in the block 
has transverse processes similar to those of the more posterior 
vertebrae. The last 3 vertebrae show neural arches, intercentra 
and possibly pleurocentra, although the units are slightly dis- 
articulated. The vertebrae in the middle of the block are covered 
by other bones. In the exposed vertebrae the neural arches are 
quite broad and the transverse processes are prominent. They 
differ little from the vertebrae in other dissorophids in which 
armor is present, but not fused. 

Seven ribs are visible on the right side, all in ventral view. 
These are attached to the 2nd through 8th vertebrae in the 
block, and so presumably are the 4th or 5th through 10th or 
11th ribs in the animal. Only the proximal 15 mm of each is 
preserved. The ribs are uniform slats, of approximately equal 
width throughout their length. The posterior edge of each is 
overlapped by the rib to the rear. The proximal ends of the 
ribs are little if any differentiated from the shaft, and have 
a flat articulating surface. Two additional ribs are present 
beneath the vertebral column. It is not possible to determine 
from which side of the animal they came, nor from what area. 

What is visible of the shoulder girdle resembles that of Dis- 
sorophus, and even more that of Cacops. The eleithrum has an 



CARROLL: DiSSOROPTTin F.VOIJ'TIOX 



199 



expanded dorsal portion extending anteriorly beyond the shaft. 
The shaft is approximately the same length as the dorsal portion. 
The clavicles are represented only by a dorsal fragment of each 




A 




armor plates 



ventral 
surface 
of armor 




B 



Fig. 10. BroiUcUus brcvis. MCZ 1424. A, Palatal view with left jaw 
in place; B, Posteianial matciial, dcirsal aiul ventral view of block. X 1- 



200 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



stem. Only the dorsal portions of the two scapulae are pre- 
served. As in Cacops, the dorsal anterior margin is slightly 
truncated for reception of the cleithrum. The left humerus 
is complete except for the ectepicondylar process distal to the 
middle of the articulating surface for the radius. The articulat- 
ing surface for the radius appears less prominent than that in 
Dissorophns. The posterior portion of the proximal articulating 
surface is expanded ventrally as in other dissorophids, and is 
recessed at its extremity. The ends are set at an angle of ap- 
proximately 70°. 

A pelvis (Fig. 11) has been associated with the referred skull 
since they were picked up together, and because it is definitely 
dissorophid in nature. The pelvis is clearly distinct from that 






Fig. 11. BroiUdlus brevis. MCZ 3272. Pelvis. A, LatiMul view; B, 
Anterior view; (', Ventral view; D, Dorsal view; E, Sacral rib. X !• 



CARROI>I. : niSSOHOPlIID KVOLr'PlOX 201 

of DisaoropJiKs angustus {vide infra) known from this locality, 
but the possibility that it beloii<>'s to Tersomius cannot be com- 
pletely ruled out since that genus, in which the pelvis is un- 
known, is common in the Archer City bone bed. 

There are very few features in Williston's descri|)tion of the 
pelvis of Cacops that do not hold for this specimen as well. The 
proportions of the tAvo differ slightly, with a larger ])ubis in 
Cacops. There are also minor differences in configuration. In 
lateral view, the dorsal margin of the ischium is straight in 
this girdle, while in Cacops it is slightly concave and there is 
a more obvious indenture in llic middle of the anterior margin 
of tlie pul)oischiadie ])late. Probably due to the relatively small 
size of the pubes, the obturator foramina are placed nearer the 
anterior margin than in Cacops. 

The blades of both ilia are broken off just dorsal to the ace- 
tabula. The inside surface of the ilium, as far dorsally as each 
is preserved, bears no markings for ligamentous attachment of 
the sacral rib such as are present in Eryops. The sutures be- 
tween the bones are difficult to determine. The sutures separating 
the ilium from the pubis and ischium can be seen laterally, 
but only the suture between the ilium and the ischium is 
determinable medially. The ventral surface of the puboischiadic 
plate shows no division into its components. 

A single pair of sacral ribs was present within the girdle, 
but neither rib was in place. From their orientation it is not 
possible to tell which was right and which was left. The sacral 
ribs are distinct from those of Cacops, but resemble somewhat 
those of Eryops. They do not at all resemble those of Dissoroph us 
multicinctus described by DeMar. The jn-oximal end of each rib 
is expanded and appears to liave only one surface of articulation 
with the sacral vertebra. Presumably, as in other dissorophids 
described, it articulated with both the transverse process of the 
neural arch and the intercentrum. A short constricted area 
separates the proximal and distal articulating surfaces. The 
shaft is curved so that there is about a 45° angle between the 
surface of the rib articulating with the ilium and the proximal 
end of the shaft. The distal portion of the i-il> is exininded 
dorsoventrally about three times the thickness of the shaft. This 
portion is large enough to cover the entire breadth of the ilium 
if the size of that bone is comparable to that of other dissoro- 
phids, so it is unlikely that there were two sacral ribs. Only 
the medial surface of the distal portion is visible due to the 



202 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

fragility of the bones, which made it difficult to clean both sur- 
faces. The central portion is thickened as a continuation of 
the shaft. There is an additional thickening on the dorsal (or 
ventral, depending on which is the right rib) margin. Both 
the dorsal and ventral margins appear to be finished bone. 

A fragment of the left femur is attached to the pelvis. The 
adductor crest is prominent as in all dissorophids. Not enough 
has been preserved for further comparison. 

Discussion : From the structure of the armor and the configura- 
tion of the skull of BroilieUus hrevis, there can be little doubt 
that this form is ancestral to BroilieUus texensis, although dif- 
fering sufficiently to be considered a separate species. 

Two fragmentary skulls described by DeMar, University of 
Texas nos. 3189-8, both from Thaxton ranch. Clay County, 
Texas, may belong to this species. According to Romer, this 
locality is probably in the Admiral Formation, slightly above 
the Archer City bone bed. The lack of any postcranial material 
unfortunately prevents definite assignment of these skulls, since 
it is primarily on the basis of armor that B. texensis, B. hrevis. 
and Bissorophus angustus are differentiated. 

DlSSOEOPHUS Cope 1895 

DiSSOROPHUS ANGUSTUS^ Sp. n. 

Figures 12, 13 and 14 

Type: MCZ 1695, partial skeleton, including right rear por- 
tion of skull, vertebral column from atlas to third postsacral 
with ribs and dermal armor, pelvic and pectoral girdles, and 
limb fragments. This is the only specimen known. 

Locality: Archer City bone bed, one mile southwest of Archer 
City, Archer County, Texas. 

Horizon: Putnam Formation, Wichita group. Lower Permian. 

Collector: L. I. Price, 1937. 

Diaejnosis: Dissorophid possessing a complete set of internal 
dermal plates above the vertebrae, and an incomplete external 
set, neither fused to the neural spines, neither exceeding in 
width the distal extremities of the transverse processes of the 
fourth vertebra. Otic notch not closed behind. 

Description: The skull of this animal (Fig. 13) is unfortu- 
nately quite incomplete. Only the portion to the right of the 

1 AngiintUK: I'roiii the Latin mcaiiin}; narrow, in reference to the narrow armor 
lihites. 



CARHoi.L : nissonoiMiin evolution 



203 



midline, hchiiid the orbit, is preserved. What is ])re.sent re- 
sembles the skull of Broiliclbis brcvis in the ])attern of orna- 
mentation and the open otie notch. It differs from that species 
in the much greater de])th of the rear portion of the skull rela- 
tive to the width of the skull table. The distance between the 



ext 




Fig. 12. Dissomphuf! nnpnstus. MCZ 169.1. X 1- 



front of the otie notch and the back of the orbit ap])ears to 
be shorter, relative to other cranial dimensions, in this sjieci- 
men. It is not possible to determine whether the ,iu<>al extends 
to the margin of the palate since the vertebral column is firmly 
affixed to the side of the skull. The right rear portion of the 
palate is also preserved. It is very similar to that of Broilidlns, 
except that the margin is much lower than the basicranial articu- 
lation. The pterygoid and ectopterygoid are covered with a 



204 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

thick shagreen of teeth. The muscle attachments on the para- 
sphenoid do not appear qnite as prominent as in Broiliellus. 
The basicranial articulation is firmly sutural. The skull is 
fractured so that the openings for the internal carotids are not 
visible. The stapes is present, but displaced to the rear. It is 
imperforate as in other Permian dissorophids. 

The occipital region is better preserved than in other dissoro- 
phids studied. The major features resemble those of Eryops 
and Tcrsomins. The occipital condyle is distinctly double. As 
in Tersomius, the otic bone is located mostly lateral to the con- 
dyles, rather than hdng mostly dorsal to these structures, as 
in Eryops. There appears to be a separate ossification, the supra- 
occipital, medial to the dorsal portion of the exoccipitals. The 
contact between this bone and either the exoccipital or the otic 
cannot be seen in the sagittal view. 

The skull is broken almost at the midline, giving a sagittal 
view of the braincase. Most of its features resemble those noted 
in Tersomius. As in Tersomius, a ventral cleft separating the 
otic and exoccipital bones allows passage for the Xth nerve. 
Anterior to the otic region there is a large gap in the wall of the 
braincase, the posterior portion of which results from a failure 
of the otic capsule to ossify completely. In front of this gap, 
the epipterygoicl is functionally a portion of the lateral wall 
of the braincase. This bone is divided into two portions. An 
anterior rod arises just lateral to the basicranial articulation and 
ascends to the skull roof. It slants medially at about a 45° 
angle to approach the midline of the skull roof. Arising from 
the base of this anterior rod, the posterior portion of the epi- 
pterygoid slopes posterodorsally and slightly medially to ap- 
proach the otic bone near the skull roof. Medial to the base of 
the epipterygoid there is a pronounced depression in the para- 
sphenoid anterior to the basisphenoid to accommodate the 
pituitary and the rectus eye muscles. There is no trace of the 
sphenethmoid. 

The postcranial skeleton (Figs. 12 and 14) is quite well 
preserved, but preparation was somewhat complicated by the 
twisting of the vertebral column into a semicircle. 

The armor is the most interesting aspect of this species. It is 
an ideal intermediate between the structure of Broiliellus and 
that of Dissorophus midticinctus. No armor was preserved 
above the first 4 vertebrae, but since the 2nd, 3rd and 4th neural 
arches are broken off, it is probable that the anterior end of 
the armor was lost in preservation, rather than missing in the 



CARROLL: DISSOHOIMIII) EVOLUTION 20.") 

livln<j: animal. Armor covers tlie otli tlir()U<i:li ITtli vertebrae. 
TIkm'c is (lefiiiitely no armor associated with the 19th vertebra, 
but the presence or absence of armor on the 18th is difficult to 
determine since the dorsal portion of the neural spine is missing 
and this vertebra is at the edge of one of the three blocks of 
matrix. The 7 posterior armor plates are similar to those of 
Broiliellus hrevis. It is not possible to determine whether ventral 
flanges were present. Between the 13th and 14th vertebrae 
there is a narrow shield dorsal to the series just mentioned, 
similar to those of the external series in Diftsorophns mnlti- 
cinctus. Since the 15th shield is unsculptured on its anterior 
edge, it is possible that a further small external plate rested 
here. The internal shields do not appear to overlap to any 
extent. In front of shield 10 (numbered in Fig. 14 D) there 
are two plates per segment : an internal plate, homologous to 
shields 11 through 17, and an external plate, homologous to 
the shield between plates 13 and 14. Shield 10 appears to con- 
sist of one plate of each series fused together, since it overlaps 
the 11th, but is itself overlapped anteriorly. The most anterior 
plate, covering neural spines 5 and 6, is anomalous since it 
overlaps an external shield. It is both narrower and longer 
than the other plates. Its left edge, and presumal)ly the right 
also, is broken off. It appears possible that it extended over the 
3rd and 4th vertebrae also, since the anterior shield in Dissoro- 
phus multicinctus is considerably longer than the remainder. 
The anterior members of the internal series are visible from 
the side and show distinct ventral flanges. The 7th and 8th 
shields each have two ventral flanges visible from the left side, 
extending anteriorly and posteriorly to the 7th and 8th neural 
spines. 

The vertebral column is well preserved in this specimen. 
There are 26 presacral vertebrae, 1 sacral, and 3 eaudals. The 
first two vertebrae are distinct from the remainder. In lateral 
view the atlas greatly resembles that of Amphihamus lyelli. It 
consists of a neural arch fused to a cylinder consisting of the 
intercentrum and possibly the pleurocentra, as in Cacops and 
Dissorophus multicinctus (Williston, 1910). Whether, as in 
those genera, there are two dorsal prongs arising from the 
centrum is not possible to tell. One projection is situated to 
the right of the succeeding neural arch, but there is no comple- 
ment on the left side. That side is damaged to the extent that 
the midline cannot be determined, so the left side cannot be 
restored on the pattern of the right. This single prong is 



206 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 





A 




eo 




asc pro 




soc 



Fig. 13. Dissorophus angustus. MCZ 1695. Skull. A, Dorsal view; B, 
Lateral view; C, Palatal view; D, Posterior view; E, Sagittal section of 
braiiiease. X 1- 



similar to, although smaller than, the neural spines behind it. 
There are small projections extending anteriorly and i)osteriorly 
just above the neural canal that aid in articulating the atlas 



CARHOLL : DISSOHOIM I ID EVOLUTION' 207 

with tlic coiulylcs and tlic axis. The iialiu'c of the surface artio- 
iilaliiifj- witli tlic occipital condyles is impossible lo determine. 
A lateral projection of the neural ai'ch foi-ms a weak ti-ansverse 
process which apparently did net hear a i-ih. A small t'i-aLiiiient 
of 1)()U(> ill fi-ont of the at his may have been pai't of a i)r()atlas. 

There are also modifications in the second vertidira ; the 
transverse processes are larjz'e and hlunl. and presumably did 
not bear ribs. No free i)leu]'ocentra are visible between the 2nd 
and 3rd vertebrae, but there is a separate intercentrum. The 
anterior zyp-apophyses are only poorly developed but the pos- 
terior ones are like those of the remainder of the column. The 
remainino' vertebrae are quite uniform as far as can be judged, 
except for diminishinji' somewhat in size behind the sacral region. 
The 3rd through 3()th vertebrae bear strong transverse processes, 
decreasing only slightly in length posteriorly. Th(\v extend 
horizontally and obliquely posteriorly as far as tlu^ margin of 
the dorsal shields. The articulating surface for the ribs is 
straight and faces slightly ventrally and posteriorly. On the 
first 21 vertebrae, it is as large as the articulating surface of 
the ribs. It becomes smaller in the sacral region. The neural 
arches are consistently 9 mm long from the r)tli to the lOth 
vertebrae; they decrease gradually to a length of .") mm behind 
the sacrum. In each of neural spines 15, 16 and 17 there is a 
vertical groove in the lateral surface for most of its length. 

The ventral units are concealed by the rib.s or other bones 
in the anterior region of the column. Where visible, the anterior 
intercentra do not appear to bear articulating facets for the 
ribs. In the region of the sacrum the ribs do articulate with 
the intercentra, but the intercentra are not modified for their 
attachment. The intercentra are uniformly crescent-shaped 
throughout the column, as they are in Cacops. The pleurocentra 
are nowhere clearly visible. 

The ribs are fairly well preserved. None were found with 
the first two vertebrae, and from the nature of the transverse 
processes it seems probable that there were none. This is also 
the condition noted in Aniphihanixs hjcUi; the condition in other 
dissorophids is not certain. Ribs are present on the 3rd through 
19th vertebrae. These ribs appear single-headed, with little or 
no articulation with the intercentra. A number are in position, 
resting directly on the transverse processes, and there is no 
room for separate capitular heads. The length increases rajudly 
from the 1st to the 5th rib, after which it decreases gradually 
for the remainder of the column. The first 4 ribs are of uniform 



208 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 

width, 4 mm, throughout their length. The 5th through 13th 
ribs have uncinate processes. The 2nd, 3rd and 4th ribs are 
covered by the scapula so that the presence of uncinate processes 
cannot be determined. The processes are all located about the 
same distance from the articulating surface, and so gradually 
approach the distal extremity of the rib. The processes increase 
in length from the 5th rib posteriorly, reaching a maximum 
length of 7 mm in the rib for the 11th vertebra, and decreasing 
sharply in the 12th. 

No ribs are preserved on the 20th through 25th vertebrae. 
Presumably the ribs in this area were similar to those just 
anterior. The proximal portion of the right rib of the 26th 
vertebra is present and articulates with both the transverse 
process and the intercentrum. The sacral ribs, on the 27th 
vertebra, are also articulated with the intercentrum. They are 
similar to, although larger than, the sacral ribs in Broiliellus 
hrcvis. There appears to be less than a 45° angle between the 
proximal end of the shaft and the surface of articulation with 
the ilium. This surface is expanded ventrally to about twice 
the Avidth of the proximal end of the shaft. It is not quite as 
extensive as the sacral rib in Dissorophus multicinctiis, but the 
surface of articulation is larger than that in Broiliellus. 

The ribs on the 28th and 29th vertebrae are similar in size to 
those on the 26th, and each has a separate area for articulation 
Avith the intercentrum, and with the neural arch. These ribs 
are not at all modified to articulate Avith the peh'is. 

The girdles are fairly well preserved. The right scapulocora- 
coid is complete although the dorsal portion is covered by the 
vertebral column. Except for its smaller size, nothing dis- 
tinguishes the scapulocoracoid from that of Dissorophus mulii- 
cinctus. The dorsal margin of the left scapula is preserved and 
shows a truncated anterior margin, similar to that noted in 
Cacops. A fragm^ent of the right cleithrum lies beneath the 
vertebral column. This bone is apparently expanded dorsally 
in a manner similar to that seen in other dissorophids. The stem 
is not preserved. Both clavicles are preserved. In configuration 
and extent they are similar to the clavicles of Cacops and Disso- 
rophus niulticincfus. The dorsal extent of the stem cannot be 
determined. The interclavicle is present, but its configuration 
cannot be determined since preparation Avould necessitate de- 
struction of the clavicles. 

The right humerus was found in place in the glenoid cavity. 
The bone was crushed, hoAvever, and presents no details Avorth 



CAKKOhL: DlSSdKUl'lllI) i;V( )LrTI().\ 



209 



descrihiii^'. Scx-ci-al toe bones wci'c foiiiid in llic \iciiiil\' of the 
forolinil). Tlic laf.ucst and most coiiiplctc is (I nun loii'/. 'IMicy 
are in no partieulai- ordef. 

The left half of the pelvic <iirdle is fairly well preserved. 
It res(Mnl)les most elosely the pelvis of Dissorophns nndticiiicfus 
(MCZ "2122) now beiii«>' studied by DeMar. It differs signifieantly 
from the pelvis associated with BroilicUus hrevis, and also fioin 
that of Cacops. The pnboisehiadic plate is much more ii])riuhl 
than in these genera. It is less erect, however, than that of 
Eri/ops. The ilium is expanded more in an anterior-posterior 
direction and also more dorsoventrally than in Cacops. its 
extent is a])])roximately the same as in Dixsorophiis mull Ifiiicl us. 






17 16 15 M 13 12 11 10 9 e 7 6 5 




Fig. 14. Di.ssoroplius nur/u.stiis. MCZ 1695. Postcrnninl skeleton. A, 
Lateral view of pectoral girdle ; B, Lateral view of pelvic girdle ; C, 
Anterior view of pelvic girdle, right side restored from left; D, Vertebral 
column, ribs and armor. X !/-• 



The posterior portion of the ischium is missing. A rrushed 
fragment of the left femur was prescMit in the acetabuluni, Iml 
no other material from the hind limb was preserved. 

Discussion: The pattern of armor of this specimen is clearly 
intermediate between that of BroilicUus and that of Dissofojjhus, 
as is the number of segments covered. While the posterior shields 
are generally like those of BroilicUus, the anterior region is 
Dissorophus-\ike in pattern. The narrowness of the armor reflects 
the primitive condition observed in B. hrevis. The possession 
of two flanges rather than a single ventral Hange pi-ojecting from 



210 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

the anterior ventral series is nnexpected in an ancestor of Dis- 
sorophus mulficincfus, but the high deoree of variability in other 
aspects of dissorophid armor, noted by DeMar, suggests that 
this is not an important distinction. In other respects this species 
is an excellent ancestor of Dissorophns multicinctus. 

An interesting aspect of the armor of this species is its re- 
semblance to that of Cacops. If the armor were fused to the 
neural spines, there would be little to differentiate the two. 
One point of distinction is the composite anterior shield, re- 
sembling that of Dissorophns multicinctus rather than that of 
Cacops, in which each vertebra has its own separate pair of 
shields. Other features of the skeleton, such as the number of 
presacral vertebrae and sacral ribs, serve to differentiate clearh- 
these two genera. 

BrEVIDORSUM^ gen. n. 

Type species: Brevidorsum profimdum. 

Diagnosis: Dissorophid possessing ridges around the orbits, 
but lacking them on the margins of the skull table. Postfrontals 
and prefrontals not meeting above orbits. Jugal not overlapping 
quadratojugal or maxilla. Room for 45-55 teeth in each jaw. Otic 
notch open. Presence of armor not known. 

Brevidorsum profundum^ sp. n. 
Figures 15 and 16 

Type: MCZ 3250, partial skull and postcranial material in- 
cluding fragments of both scapulae and cleithra, portions of 
both humeri, left femur, left tibia and fibula, one or more verte- 
brae with attached ribs. 

Locality: North of the west fork of the Trinity River, Texan 
Emigration and Land Co., Section 1834, Archer County, Texas. 

Horizon: Near Pueblo-Moran boundary, Wichita group, Lower 
Permian. 

Collector: A. S. Romer, 1948. 

Diagnosis: Same as for genus. 

Description: Most of the right side of the skull is preserved 



'i Breridorsiiw : I'lom the Latin brcris, meaning short, and ilnrsiim (ni'Utor) 
meaning bacic or ridge, in reference to the limited extent of the ridges on the 
skull. 

2 Profundum: from the Latin nie.ining deep, in reference to the depth of the 
bacij of the skull. 



fARKoi.r. : Dissouoriiii) i:\()i,r'i'i()X 



211 



(Fig. 15), lacking- only the nasal ivi^ion ; only a i'vw fragments 
of the left side of the skull Uihlc and palate are visible. The 
general characteristies of the skull are those common to all 




mTnnnmr 

c 

Fig. 15. Brevidorsum profiindum. MCZ 3'J50. A, ])orsal view; B, 
Lateral view; C, Lateral view restored. X 1- 



212 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

Permian dissorophids : a prominent otic notch, open in this 
wenus, and large orbits which gain contact with the frontals. The 
skull table is somewhat deeper than in the majority of dis- 
sorophids, and as a consequence the skull roof descends in a 
straight line toward the nasal region. The teeth are of the same 
dimensions as those of most other dissorophids ; if the skull were 
restored using the pattern of other members of the family, 
there would be room for approximately 51 marginal teeth in each 
jaw. There is evidence of a bony eye plate in the right orbit. The 
skull is probably close to adult size, since it is larger than those 
of other Wichita dissorophids. The closure of the sutures is 
complete. 

The most important characteristic of this skull is the pattern 
of ornamentation. Ridges surround the orbits and extend onto 
the nasal region. One ridge lies dorsal to each orbit, arising on 
the prefrontal anteriorly and passing back across the frontal, 
postfrontal and onto the postorbital. A second ridge diverges 
from the first in the prefrontal and extends toward the postero- 
medial margin of the lacrimal. It terminates at the posterior 
edge of that bone. A short ridge occurs on the orbital margin of 
the jugal, but fails to reach the postorbital. In the middle of 
the postorbital there is a shallow triangular depression, sur- 
rounded by slight ridges. This pit is in the same position as a 
similar feature in Cacops. There is also a small pit in the lacrimal 
just beneath the orbit, and another in the prefrontal. This pat- 
tern is essentially the same as that observed in DissoropJins and 
Broiliellus; it differs from these genera in lacking ridges on the 
rear of the skull table. The only ornamentations in that region 
are small tuberosities on the postparietals and parietals. One 
character it shares with Tersomins, in contrast to Broiliellus, is 
that the jugal does not overlap the maxilla or quadratojugal. 
The pattern of ornamentation suggests an intermediate condi- 
tion between the smooth-skulled dissorophids of the Pennsyl- 
vanian and Tcrsomius, and the typical genera of the Permian, 
Broiliellus and Dissorophus. 

The postcranial material is poorly preserved and was freed 
from the matrix only with great difficulty. The proximal portion 
of the right humerus is preserved only well enough to identify 
it as such and note general similarities with other dissorophids. 
The left femur (Fig. 16 A) is fairly well preserved, lacking only 
the most proximal portion. The adductor ridge is prominent as 
is common in dissorophids, but does not extend distally as far 
as in Cacops. The left tibia (Pig. 16 B) is similar to that of 



CARKOIJ.: DISSOKOIMIID KVOI.UTION 



213 



Cacops, but with a nanowiM- slial'l. Only tlic dofsal portion of 
the left scapula was preserved, it lias a slijiht anterior trunca- 
tion as was noted in Broilicllus hrcvis and DissoropJius ancjustus. 
A fra^jnient of the cleithrum is attaclu'd. The rciiiaininn' hones 
are too fragmentary for meaningful description, or were dam- 
aged in removal of the bones mentioned. One or two vertebrae 
are preserved, but unfortunately lack the neui-al spines. The 
dorsal portion of the block was eroded and so determination of 
the presence or absence of armor is not possible. 

Diaciission : The characters of this animal as well as its strati- 
graphic position suggest that it was transitional between the un- 
onianiciitcd species of llie Penusylvanian, and liroilicUu^ and 




A 







Fig. 16. Brcridorsum profundinn. MCZ 3250. A, Fcimir; Vy, Tibi:i, in 
posterior, anterior, lateral and medial views. X 1- 



214 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

Dissorophus. It seems sufficiently distinct from both of these 
groups, however, to warrant placing it in a separate genus. 

The taxonomie status of several additional species is not clear, 
and should be discussed before considering the evolutionary 
pattern of the Permian dissorophids. 

ASPIDOSAUPJJS Broili 1904 

ASPIDOSAURUS NOVOMEXICANUS WillistOU 1911 

Figure 17 

Aapidosaurus novomexicanits Williston, 1911, p. 20. 

Broiliellus novomexicanus (Williston), Laiigston, 1953, p. 380 (in part). 

Type: YPM 810, skull and skeleton. This is the only known 
specimen. 

Locality: El Cobre Canyon, Rio Arriba County, New Mexico. 

Horizon: Roughly equivalent to tlie Moran of Texas, AVicbita 
group. Lower Permian. 

Revised diagnosis: Dissorophid with a single layer of narrow 
armor plates, in the process of fusing to the neural spines. Indi- 
vidual plates not in contact with one another. Some plates 
longer than others; total number of plates unknown. Open otic 
notch. Room for 45-55 teeth in each jaw. Twenty-one presacral 
vertebrae. One sacral ril) ; anterior ril)s with uncinate processes. 

Description: Although additional specimens have been referred 
to this species by Case, Williston and Mehl (1913), and by Lang- 
ston (1953), they clearly belong to a separate genus and will be 
discussed under Conjunctio. Several changes must be made 
fi'om the original description of this species, since it was based on 
an incomi)lete conception of other dissorophids. A complete 
description is still difficult clue to the fragmentary nature and 
poor preservation of the specimen. 

Both the skull roof and the palate are preserved behind the 
nasal region, together with fragments of both jaws. All the bones 
of the skull roof lack their original surface and so no sign of 
typical dissorophid rugosity can be seen nor denied. A depres- 
sion in the middle part of the skull table is ju'obably only a 
result of post-mortem distortion, since the skull as a whole 
is skewed to the right, and the left side is turned under. The 
pattern of most of the cranial bones is readily determined and 
differs little from that of Dissorophus, Broiliellus or Tersomius. 
It is not possible to determine whether the maxilla and quadrato- 
jugal were overlapped by the jugal since the surface of the 



CARROLL: DISSOKOIMIII) i:V(MJ"ri().V 



215 





Fig. 17. AspiJosaurus novomcricanus. YPM 810. A, Dorsal view of 
skeleton; B, Lateral view of skull; C, Detail of armor attachment, anterior 
and lateral views. X 1/2. 



216 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

latter bone is eroded. The region of the otic notch is well enough 
preserved to determine with certainty that the notch was not 
closed posteriorly. The cheek region is relatively deep. 

Fragments of both lower jaws are preserved, the left showing 
one tooth, similar in size to those of Dissorophus or BroUidhis. 
There would be room for 45-55 teeth of this size in each jaw. 
Only the medial portion of the palate is preserved. The basi- 
cranial articulation is apparently sutural. The ventral flanges 
of the parasphenoid, noted in Broiliellus for muscle attachment, 
are not apparent, but this may be due to faulty preservation. 
A fragment of the left stapes is preserved, but apparently none 
of the l)raincase. 

A large portion of the postcranial skeleton is present, but it 
is all poorly preserved. Narrow armor plates are preserved 
dorsal to the 3rd through 9th vertebrae. It cannot be determined 
whether there were additional plates. None are fused to tlie 
neural spines, but all appear in the process of fusing. The first 
and seventh plates are longer than the remainder, but none of 
the plates are in contact with one another. The entire dorsal 
surface of each plate is sculptured, so there was apparently no 
external layer of armor. Each plate is in the shape of a very 
open, inverted V. 

There are 21 presacral vertebrae. Their most important fea- 
ture is the great thickness of the neural spines beneath the armor 
plates. As was mentioned in the original description, the anterior 
ribs have marked uncinate processes. The single sacral rib has 
a wide area for articulation with the ilium. Fragments of the 
shoulder girdle, one ilium and pieces of the front limbs are 
present, but the surface is gone from all of the bones. 

Discussion: According to Langston and to Romer, the El Cobre 
Canyon locality where this specimen was found is lower than 
the typical AIjo Formation, i.e., perhaps ecjuivalent to the Moran 
of Texas. This specimen is hence older than any other armored 
dissorophid known, with the exception of isolated armor plates 
from the Moran of Texas. The nearest relationship of this 
species appears to be with Aspidosaurus chiton from tlie similar- 
ity of the armor, since both animals have armor of different 
dimensions in different regions of the column. Although not 
attached, the armor of A. novomexicanus shows signs of becoming 
connected, including expansion of the terminal portion of the 
neural spines. Langston placed this species in the genus IhoUid- 
Iks on tlie basis of the referred specimens and not the type, 
wliicli lie was unable to stud}'. 



CARROLL: niSSOROlMIII) KVOLTTIOX 



•217 



ASIMDOSALRI'S S]). 

Fimii'c IS ami Plate 1 

The earliest dissorophicl aniior known from Texas consists 
of three neural spines with fused plates from the Moran Forma- 
tion (MCZ 2740). These were collected by L. I. Price in 1935, 
one mile northwest of Padgett, northeast part, Wm. Tryndale 
survey, Young (,'ounty, Texas. They resemble in a general way 
the armor associated with the tyi)e skull of Aspidosanrus chiton 
from the Arroyo ( Broil i, 1904). One piece has a longitudinally 








Fig. 18. AsiiiilosaKni.s sp. MCZ 2740. Tliree neural sjiiiics with fusee 
ariiior iu dorsal, lateral and anterior (or posterior) views. X 1- 



and transversely expancU'd dorsal jjortion in the shape ol' an 
inverted V, with })itting over all hnt the midline of the dorsal 
surface. Another has only a small expansion of the end of the 
neural spine; this is sculptured in the mid-portion, but not on 
the anterior or posterior margins. The spines i-esemble. re- 
s])eetively, figures 13 and 14 in i)lale VI of Broili. A third, small 
shield is expanded transversely, bnt not longitudinally, and is 
either not sculptured, oi- else the surface has w(»atliere(l off. 



218 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

Armor of a similar nature has been found in the following 
additional localities and horizons of the Texas Permian. Putnam 
Formation : MCZ 1701, Archer City bone bed, Archer County. 
Admiral Formation : MCZ 2745 and 3162, Briar Creek bone bed. 
Section 32, Dallas County school land, Archer County. Belle 
Plains Formation: MCZ 2528, Wm. Mann survey, Section 40, 
A-271, southwest of Dundee, Archer County; and MCZ 2529, 
four miles east of Rendham, southwest part of Fayette County 
school land, Baylor County. In all but the last of these localities, 
several different shapes of armor are present, but all seem to be 
within the range of variation of the armor in Aspidosaurus 
chiton. 

Other armor, of a much more bizarre nature, is found in 
considerable quantity at Rattlesnake Canyon in the Admiral 
Formation (MCZ 1477, Plate 1), and also at Tit IMountain in 
the Belle Plains (MCZ 2746). The pattern of this armor varies 
from that observed in Aspidosaurus chiton to that of Platyhy- 
strix. This type of armor could have evolved from that found 
in the Moran Formation, but since nothing except the armor 
is preserved, it cannot even be definitely stated that this animal, 
or animals, was a dissorophid. 

CONJUNCTIO' gen- n. 

Type species: Conjunctio multidens. 

Diagnosis: Dissorophid with a single layer of narrow armor 
plates, the anterior plates fused to the neural spines; otic notch 
not closed posteriorly; 70 or more teeth in each jaw. Pattern 
of cranial ornamentation similar to that of BroilieUus and Dis- 
sorophus, ])ut less pronounced. Jugal overlapping quadratojugal 
and maxilla. Median rostral fontanel. 

Conjunctio multidens- sp. n. 

Afipidosaurus novomexicanus, Case, Williston and Mehl, 1913, p. 7. 
Broiliclliis novotnc.ricanus, Laiigston, 1953, p. 380 (in part). 

Type: CNHM 673, skull and associated postcranial material 
including femora, humeri, scapulae, pelvis, section of vertebral 
column and armor. Illustrated by Case, Williston and Mehl, 
1913, figure 7. 



'^Coiijiniclio: U'inn the Latin coiiiiiiirtio (feminine), nieanin.L,' a jdinini; tojjetlioi'. 
in rclorcncc to tlic fusion of armor to tlic neural spines. 

'^Multidens: from the Latin miiltun, meanin,!^ many, and dcitu (masculine) 
meaning teetli. 



CARRoiJ. : nissoRDriim evolt'tion 219 

Ldcalihi: "West side ol' Piicii-o Kivcf opijositc EI Rito, New 
Mexico. 

TInrizn]): A ho Format ion, Lower I'ei'iniaii. 

CoUrctor: Paul C. Miller. 

Diafjnosis: Same as for s'enus. 

Referred specimen: UCMP 4010:1, skull. 

Localitii: ("amp (jnarry V-2814. one mile southeast of Arroyo 
de Ag'ua, New Mexico. 

Horizon: Abo Formation, Lower Permian. 

Discussion: From re-examination of the type of Aspidosaurus 
novomexicanus it is evident that the two specimens that iiave 
been referred to that species belong to a distinct genus and 
species. In both CNIIM 678 and UCMP 40103 there is room for 
70 or more teeth in each jaw, wdiile in the A. novomexicanus type 
the tooth size of the one or two teeth present indicates that there 
Avould be room for only 45-55 teeth. Differences in tlie armor 
are also distinctive. In Aspiclosauriis novomexicanus none of 
the shields are fused to the expanded neural spines. Only sevoi 
shields are preserved, none of which is in contact with the others, 
and the first and seventh are longer than the remainder. In the 
Chicago Museum specimen, the anterior, although not the pos- 
terior, shields are fused to the neural spines, and all the shields 
are in contact with the preceding and succeeding jilates. The 
total number of shields is not known, but it certainly exceeds 
seven, and all of the shields are of approximately the same 
size. The Universit.y of California specimen has no posteranial 
material. 

As was pointed out l)y Langston, the general eonfigui-ation 
of the skulls and particularly the pattern of ornamentation of 
the specimens that have been referred to Aspidosaurus novo- 
mexicanus are very similar to those of BroilicUus. There are, 
however, other features of the skull and particularly of the armor 
which separate the two groups. Three features differentiate the 
California and Chicago skulls from BroilicUus hrevis and B. 
texe7isis. The former have a great many more teeth, the pattern 
of ridges is more subdued, and there is a median rostral fontanel. 
The width of the armor is on the order of that obsei-ved in 
Broiliellus hrevis. The armor differs, however, not only in the 
fusion of the anterior plates, but also in the shape of the indi- 
vidual shields ^ relatively flat in B. hrevis, and in the shape 
of an inverted V in these specimens. 

Both specimens of Conjunctio multidens were collected from 



220 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

the Abo Formation near Arroyo de Agua. According to Eomer, 
the Abo is roughly equivalent to the Putnam Formation, perhaps 
including the upper portion of the Moran and the lower Admiral. 
Their stratigraphic position as well as their morphology sug- 
gests derivation from B. hrcvis or a closely related predecessor. 
They clearly represent a different line of development from that 
expressed by BroilieUus hrevis and B. texensis, and so should 
be placed in a separate genus. 

CoNJUNCTio sp. 
Figure 19 

A third specimen (MCZ 2369) obviously referable to Con- 
jnnctio has been found in the Admiral Formation of Texas. It 
was collected by Dr. Romer in 1950 from the Halsell Hill locality, 
Section 19, Halsell subdivision, Clay County, Texas. Like the 
New Mexico specimens, it has a large number of teeth, a median 
rostral fontanel and a similar pattern of armor. No specitic 
features separate it from the other members of the genus, except 
its place of discovery. This, however, is itself quite significant 
since the Texas and New Mexico land areas were separated during 
the Permian by a long arm of the sea, and only one vertebrate 
species, Zatrachys serratus, has been reported in both areas 
(Langston, 1953). For this reason I hesitate to place this speci- 
men in the same species as the New Mexico specimens, despite 
their morphological similarities. All three specimens are of 
about the same geologic age. 

The specimen includes the skull and fragments of both lower 
jaws, about 14 vertebrae with ribs and armor, portions of the 
shoulder girdle and front limbs. Tlie skull roof is almost com- 
plete, lacking only the right front margin, the back of the skull 
table and the rear portion of the upper jaws on both sides. The 
skull has been greatly flattened, particularly in the antorbital 
region, distorting somewhat the outline of the skull. If restored 
to its original shape it would resemble closely the skull descril)ed 
by Langston which I refer to Conjunctio multidens. The i)or- 
tion of the skull posterior to the orbits is relatively short, as in 
other dissorophids from the lower ]^art of the Wichita. The 
right tabular is intact and there is no bar closing the otic notch. 
The pattern of ornamentation is the same as in other members of 
this genus. The jugal overlaps the quadratojugal and maxilhi 
as in BroilieUus hrevis. A scrap of bone is present in the left 
orbit, presumabl\- representing tlie remnant of a supi'aorbital 



rAKH()i,F>: nissoKoiMMi) i:\()i,r'i'iON 221 

plate. Tliere is a sn^-ocstion of sclci-otic plates in llie same orbit. 
Since selerotie plates are present in the I'ennsylvanian dissoro- 
pliids, tliey presumably existed in all of the Permian members 
of the family as well. 

Most of the suture lines ai-e visible, or can be readily restored 
by comparison of the two sides of tlie skull. Tbe confi«;uration 
of the individual bones diff(M-s from that of Broilicllns or 7Vr- 
somius only in the "Teater length of the nasals as compared vith 
the frontals. This, of course, is acceutnatcd by the fiattening of 
the forepai't of the skull. The median rosti-al fontanel is in the 
same position as is the internai'ial bone in Tcrsoniiiis, and of 
about the same size. The left lower jaw is fortunately displaced 
inward, allowing all of ihe teeth in the upper jaw to be visible. 
In spite of a short gap in th(> tooth vow in the maxilla, there are 
48 teeth, with room for 16 more, not counting the ga]^ which 
could have accommodated about 6. The premaxilla has 10 teeth, 
with room for 6 more. The teeth are considerably largei- in the 
premaxilla and anterior portion of the maxilla than they ai'e 
in the posterior region of the upper jaw. All of them ai'c bi-oken 
off, but would probably havc^ been a millimeter or two in length. 
The jaw fragments are too incomplete to describe. 

Two small blocks of matrix containing a number of vertebi-ae, 
ribs and armor were found together with the skull. The bones 
are broken and jumbled in a very hard matrix, so few details 
are visible. The atlas and axis are not present and other anterior 
vertebrae may also be missing. The neural spines of the first two 
anterior vertebrae preserved are truncated and the armor is 
lost. The 3rd through 9th vertebrae have fused armor plates. 
In the second block of matrix, probably contiguous with the 
first, the first vertebra is truncated dorsally while the second 
has a fused armor plate. If it is assumed that only the atlas 
and axis are missing from the anterior block, the fii'st 13 verte- 
brae have fused armor plates. The neural spine of the 14th 
A'ertebra is complete and lacks fused armor. A free armor plate 
lies close to this vertebra, but could equally well have come from 
further on down the column. The 15th and 16th vertebrae have 
broken neural spines ; no others are present in the block. Only 
the single free plate was found. 

None of the fused plates are complete; all have been broken 
on the margins. Each had been about 5 mm long, and perhaps 
10 mm wide. The sides meet at an angle of about 135°. On 
the dorsal surface, immediately above the neural spine, the 
armor is not sculptured. The sides, hoAvever, are deeply pitted. 



222 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 



mrf 










Fig. 19. Conjunctio sp. MCZ 2369. A, Dorsal view of skull; B, Voiitial 
view of skull; C, Right and left views of blocks containing postcraiiial 
material; D, Detail of free armor plate in dorsal and anterior views. 
X 3/4. 



CARROLL: DISSOROI'lIII) KVOU'TIOX 223 

The siiitiic piece of free aniioi- is well pi-eserved. A<j;iin it is in 
the sliape of an inverted V. the sides ineetin<|- at an ani^le of 
about 100°. Eaeli side is about .'! tnin wide aiul .") mm lon^-. An 
unsculptni-ed rid'^e runs aloufj the line of juueture of the sides 
which are s('ul])tured with pi-oinineut pits except for a narrow 
strip on each mai'^nn. In contrast to C mulfulcns tlioro does 
not appear to have been any ventral projection from the ai'iiior 
])late. Tliei-e is lu) evidence of a second layer of armor. 

The vertebrae themselves are poorly presei'ved ; none of the 
central elements are visible. The anterior neural arches bear 
large transverse processes, similar to those of other dissorophids. 
The neural spines are expanded laterally beneath the armor to a 
lesser extent than in Aspidosaurns novomcricanufi. Those be- 
neath the fused i)lates are elongated anteroposterioi-ly, with the 
neural spines of the 7th and 8th vertebrae appearing to be in 
contact. Other vertebrae are not well enough preserved to deter- 
mine the extent of their neural spines. 

A number of ribs are preserved, those in the anterior portion 
of the block bearing ])rominent uncinate processes. None of the 
ribs are sui^ciently complete to give dimensions. 

Fndiagnostic fragments of the right scapula and cleithrum 
are present along the vertebral column. Humerus, clavicle, 
radius, ulna, and scraps of other limb bones are present bet^veeu 
the lower jaws. All are either too incomplete or distorted to 
give any description. Their size and general configuration indi- 
cate that they probably belong with the skull. 

Interrelationships of the Permian Dissorophids 

Trrsomius texensis, although the most primitive of Permian 
dissorophids, is not a likely ancestor for the remainder of the 
group. It has at least two specializations not found in any later 
dissorophids : the possession of a second pair of vomerine teeth, 
and the presence of an internarial bone. The earliest specimen 
of Tcrsoin.ius, MCZ 1911, from the Pueblo-Moran boundary, may 
lack these peculiarities, but distortion in the nasal region pre- 
vents definite determination. In all probability the internarial 
bone was smaller than in the Putnam specimens, if not altogether 
missing. The second pair of vomerine teeth is not visible, but 
these are small in other specimens of Tersomius, and may easily 
have been overlooked and removed during preparation. The 
other characters of this skull correspond to those of other speci- 
mens of Tersomius. Evidentlv there existed in the Pueblo or 



224 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

perhaps in the late Pennsylvanian a species of Tersomius lacking- 
the specializations of T. texensis, which gave rise to the dissoro- 
phid genera with ornamented skulls. 

The changes between Tcrsomins and Brevidorsiim, the earliest 
ornamented genus, are relatively slight, at least in cranial anat- 
omy. The skull roof behind the orbits becomes elongated relative 
to the leujgth of the jaw suspensorium so that the end of the 
(juadrate lies even with the end of the tabular, the angle be- 
tween the skull table and the cheek region l:)ecomes sharper, 
the distance between the orbit and the otic notch becomes shorter, 
and the skull begins to show signs of ornamentation. Since 
the palate is not well preserved in the single specimen of Brevi- 
dorsum, it is impossible to tell whether the sutural basicranial 
articulation possessed by later dissorophids was developed. 

Brevidorsuni appears to have been ancestral to Byoiliellus and 
Dissorophus. The simple nature of the armor in BroilieUns sug- 
gests that that genus evolved first, and that secondary elabora- 
tion has produced the pattern of armor seen in Dissorophus. 
Skull changes between Brevidorsuni and Broiliellus are restricted 
to development of ornamentation and reduction in the depth 
of the back of the skull tal)le. Lack of postcranial material in 
Brevidorsuni precludes determination of the time during which 
armor first appeared. 

Dissorophus and Broiliellus had definitely become differenti- 
ated from one another by the Putnam, although neither had 
developed all of its definitive characters by this time. It is 
apparent that Broiliellus hreuis, B. texensis, and a third species 
from the Arroyo (being described by DeMar) represent succes- 
sive stages in one line of evolution. Between the first two species 
the armor grew greatly in width, while throughout the series 
the skull developed more and more prominent ridges and tuber- 
osities. Dissorophus angustus and D. multicinctus represent a 
similar line of evolution. Between these two species the armor 
increased greatly in width, and extended caudally to several 
additional segments, while the otic notch liecame closed pos- 
teriorly. 

Conjunctio evidently arose from a species near the base of 
the Broiliellus line. It may liave arisen either from B. hrcvis, 
or a closely related antecedent species. Not only have the 
anterior plates become fused, but additional plates have been 
added posteriorly and the shape of all of the armor has been 
altered. If there were any increase in the width of the individual 
plates, it was slight. 



("AKKOLL : DISSOKOI'IIII) KVOLrTIOX 



225 



DeMar, on tlic basis of flip armor, considered Cacops and 
AUgeinosaurus close to Aspidosaurus, and oidy distantly related 
to Broilidlus and Dissorophus. The discovery of B roil i ell us 
brevis and Dissorophus angustus, as well as consideration of 
Conjunctio, reveals that neither the width of the armor nor its 
fusion serves to separate the two groups. 



PHYLOGENY OF THE DISSOROPHIDAE 



Belle Plains 



fl 1 'l £ 

"^J 5 El ^1 2 

'' &Qi Si . g 

o I in c Q E 

9 ' ? ? '" o 

SI ^ S e ^ 

6 „' o en, u I c 



.7. 



Aspioosaurus novomexiconus 
revtdorsum profundum 



[J Nyr any 
= Linlon 



Pennsylvomon 



Amphibomus CQlliprepes 
I,,-'' Amphibamus lyelli 



Mozon Creek ) Ampmbomus grandiceps 



Pans shoie 



Arkanserpeton orcualu 



Fig. 20. Phytogeny of the Dissorophidae. 



As was mentioned earlier, the pattern of armor in Cacops 
could have evolved simply by fusion of the ventral series of an 
animal with the pattern of Dissorophus angustus. Less likely 
would be the development of pitted, expanded neural spines 



226 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

beneath a single layer of armor from an animal with the pattern 
of Broiliellus hrevis. The time gap between Cacops and the early 
species of Broiliellus and Dissorophus is certainly great enough 
to allow evolution of the characters that separate Cacops from 
the other genera, such as reduction in the number of presacral 
vertebrae and development of a second pair of sacral ribs. From 
the information now available, the most likely ancestor of Cacops 
would be a closely related predecessor of Dissorophus avfjustiis 
in which there was no fusion of anterior armor plates, but in 
which the external series of armor had begun to develop. Both 
internal and external series must have then extended posteriorly, 
while the internal layer became fused to the neural spines, as 
did the anterior plates in ConjuncUo. The posterior closure of 
the otic notch must have occurred independently in Cacops and 
Bissoroplnis. Evidently Cacops and Alegeinosaurns are closely 
related and so presumal)ly diverged from one another a con- 
siderable length of time after the acquisition of a common pat- 
tern of armor. 

If any form is to be separated from the remainder of tlie dis- 
sorophids on the basis of armor, it would be Aspidosaurus, since 
all species for which sufficient information is available have two 
or more sizes of armor on a single animal, a situation not known 
in any of the other dissorophids. The skull of A. chiton is un- 
mistakably dissorophid in the possession of prominent otic 
notches and the pattern of cranial ridges described by Broili. 
However, the skull differs from that of all other dissorophids, 
with the exception of a genus being described by DeMar, in the 
great length of the face anterior to the orbits. The variation in 
the configuration of the armor along the vertebral column is 
particularly evident in the type of A. chiton, in which there is 
little question that all of the variants belong to the same animal. 
In Aspidosaurus novomexicanus, which is a much earlier species, 
the variation is not so striking, but the first and seventh shields 
are definitely larger than the remainder. Unfortunately, much 
of the armor which has been attributed to this genus was not 
found with other remains, and so definite association with this 
genus or even reference to the Dissorophidae in general is not 
always certain. The information now available suggests that 
there are probably a number of fairly closely related genera 
among the forms now called Aspidosaurus. These ]n'obably 
evolved from the remainder of the dissorophids early in tb'> 
Permian or late in the Pennsylvanian. If A. novomexicanus is 
accepted as an early member of this group, it is probable tliat, 



CARROLL: DISSOROPIIID EVOLUTION' 227 

as will] the otlicr (liss()r()|)li!(]s. the ai'iiior fii-st dcvcloppd as 
separate dci'inal ossifications situated dorsal to the neural spines, 
secondarily beeoniinu' fused. Tf this were the case, there may 
have heen a connnon ancestor of hotli the Aspidosaurus u-roiip 
and the reinaindei- of the dissoi-ophids that had a small numl)er of 
narrow, unfused arnioi- jilates above the anterioi- i'e<:ion of the 
vertebral column. Tt is at least possible that Brcvidorsum }>ro- 
fuvfhtm or a closely related predecessor had these characteristics. 
Tn this discussion of phylogeny there has been no attem])t to 
separate the evolutionary line that occurred in Texas from that 
developed in New Mexico. Such a separation is simply not pos- 
sible with the limited number of j^enera known from New Mexico, 
and the limited time span of the New ]\Iexico beds. 

PENNSYLVANIAN DISSOROPHIDS 

Since dissorophid remains are present in the very lowest beds 
of the Texas Permian, it is natural to look for their antecedents 
in the Pennsylvanian. Dissorophids have been described from 
Mazon Creek (Greoory, 1950), and members of this family have 
been mentioned from the fauna of Nyrany. Bohemia, and from 
the Paris shale of Kansas (Romer, 1947). The best preserved 
Pennsylvanian dissorophids, however, are from Linton, Ohio. 
Several specimens pertainiufy to members of this family have 
been discovered by Dr. Baird during his extensive preparation 
of that fauna. Because of the investing matrix, the early descrip- 
tions of this materia] were rather incomplete and led to the 
erection of a number of genera. It now appears that all of the 
dissorophid material from Linton belongs to a single genus and 
species. This species resembles Amphihamu^ f/randiccps in many 
features, but is sufficiently ditferent to be placed in a separate 
species as Amphihamus lyelli. 

Amphibamus LYELLI (Wymau) 
Figures 21-25; Plate 2 

Raniceps Iijrlli Wyman, 1858, p. 168. 

Pelion lyelli (Wyman), Cope, 1868, p. 221. 

Tuditanus mordax Cope, 1874, p. 274. 

Diceratosaurus punctolincatus, Moodie (not Cope, 1875), 1909, p. 25. 

Diccratosaurm punelolinratus, Moodie (not Cope, 1875), 1916, p. 118. 

Diceratosaurus brevirostris, Eomer (not Cope, 1874), 1930, p. 91. 

Platyrhinops mordax (Cope), Steen, 1931, p. 865. 



228 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 

Type: AMNH 6841, skull and complete skeleton. 

Referred specimens: AMNH 2566, cranial fragments; BM 
(NH) K.2670, skull; USNM 4461, partial skeleton; MCZ 1277, 
lower jaws and palate. 

Horizon and locality: Upper Allegheny. All from Linton, 
Ohio. 

Revised diagnosis: Primitive dissorophid. No cranial orna- 
mentation, pre- and postfrontals meetino; above orbit. Seventy 
to eighty teeth in each jaw. No armor. 

Descripiion: The skull roof of the type specimen of Amphi- 
hamus lyelli (Fig. 21 A) is nearly complete, although slightly 
disarticulated at the margins. It is flattened in the manner of 
all Linton material, with the skull roof forced almost into the 
plane of the palate. The only portion of the skull that is missing 
is that anterior to the external nares. The occipital region ex- 
tends horizontally behind the skull table, but shows few details. 

TABLE 3 
Cranial Dimensions of Amijliihamus 



Length of cranium to extremity of 

quadrate 
Length of cranium along midline 
Greatest width of cranium between 

quadratojugals 
Least width between orbits 
Transverse diameter of orbits 
Longitudinal diameter of orbits 
Distance from center of orbit to 

quadrate 
Distance from center of orbit to 

front of skull 
Distance of pineal from back of 

skull roof 
Back of orbit to front of otic notch 



1 Measurements taken from drawing of specimen. 
Dimensions of specimens are to the nearest millimeter. 



The displacement of the marginal bones, together with the gen- 
eral compression, renders exact determination of dimensions 
difficult. It is about half the size, in any linear dimension, of 



Am 


IJliibnmus 


hjcUi 


Amphibamus 
calliprcixx 


T.vpe 
AMNH I5M(NH) 
6841 R.2670 


1 ;\icz 

1277 


nM(NH)i 

K.2817 


31 


— 


64 


— 


26 








40 


32 


57 


56 


51 


8 

10 

9 


19 


— 


14 


14 


— 


— 


17 

14 

6 


~ 


" 


~ 


11 


— 


9 


4 


9 









CARROLL: DISSOROPIIID KVOH'TIOX 



229 



MCZ 1277 and BM(NH) R.2670. The closure of the sutures and 
the high degree of ossification of tlie skeleton, however, indicate 
tliat this specimen was an essentially mature individual. 

The general skull shape closely resembles that of Tersomius -. 
large, closely-set orbits, deep otic notches and a roughly tri- 
angular outline. There can be no question of the supratemporal- 
tabular suture as there is in A. grandiccps. The tabulars are 
small bones extending beyond the posterior margin of the skull 
table, slightly disarticulated from the supratemporals. The post- 
parietals are relatively larger than those in A. (jrandiceps but, 



pm 



ppc 






Fig. 21. Amphibamus hjelli. A, Skull roof, AMNH 6841; B, Palate, 
AMNH 6841; C, Palate, MCZ 1277. X 1- 



230 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 

like the tabulars, smaller than the corresponding units in Ter- 
somius. The area of the skull table behind the orbits is shorter, 
relative to the total length of the skull, than that in Permian 
genera, but perhaps slightly longer than in A. fjrandiceps. 

The bones ventral and anterior to the otic notch are displaced 
and partially obscured so that little can be said of them. The 
bones of the orbital margin differ from those of Permian dissoro- 
phids in that the pre- and postfrontals are in contact above the 
eye as they are in A. grandicops. The jugals and lacrimals may 
make slight contact beneath the orbit, but this is not certain. 

The medial bones of the skull roof differ little from those of 
other dissorophids except that the frontals do not enter the 
orbital margins. The pineal opening differs from that of the 
other species of dissorophids only in the better preservation which 
shows the presence of a circular ridge surrounding the opening. 
The anterior ends of the nasal bones are presumably lost along 
with the posterior margins of the premaxillae ; at least, the 
adjacent margins of these bones cannot be made to match. Only 
the general position of the external nares can be determined. 
There is no sign of the septomaxillae. The front margins of 
the premaxillae can be determined by the position of the lower 
jaws. It is not possible to determine the presence or absence 
of an internarial bone. 

The maxillae are both turned under the edge of the skull so 
that only their dorsal margins can be seen, together with portions 
visible through the orbits. Teeth are visil)le in side view in front 
of the right orbit ; they will be described together with the 
palate. 

Numerous pieces of sculptured bone are visible in Ijoth orbits. 
They are evidently remains of palpebral cups such as are present 
in Tersomius. Six sclerotic plates are visible beneath the left 
orbit, and two beneath the right in MCZ 1277. Presumably the 
animal had a ring of sclerotic plates similar to that described by 
Watson in Amphihamus grandiccps. 

Like the type, the British Museum skull BM(NH) R.2670 
has been subjected to crushing, which has disturbed the margins 
of the skull and forced the side walls into the same plane as 
the skull table. Restoration of these features produces a con- 
figuration very similar to that of the type, except for the greater 
distance between the orbits in BM(NII) R.2670. It is easy to 
interpret this difference as resulting from the larger size of 
this specimen. Fragments of the palpebral cups were noted by 
Steeii ill the same position as in the type. 



CARROLL: DISSOROPIIID KVOLT-TrO.V 231 

The jialalo (Fij>s. 21 B and (' ) is similar in liciici-al 1o that of 
Permian dissorophids. Detailed structure is difficult to deter- 
mine, however, since all of the specimens studied have a tliick 
layer of denticulate "skin" covering most of the surface of the 
palate. The posterior repion of the pterygoids can be seen in 
tlie Britisli Museum specimen, with the exception of the basi- 
pterygoid articulation. This region is unfortunately obscure in 
the other specimens as well. The anterior portion of the ptery- 
goid is also missing or obscure in all of the specimens. Enough of 
the vomer is visible in AMNII 2566, howevei-, to indicate that 
the pterygoid did not reach that bone. Both ectopterygoids, each 
bearing one tooth, are present in BM(NH) R.2670, although 
somewhat disarticulated from the remainder of the palate. The 
relative position of the ectopterygoid can be judged in MCZ 1277 
since the ectopterygoid tooth has penetrated the left lower jaw. 
The palatine bone and accompanying tooth can be seen only in 
AMNH 2566. Unfortunately, even in this specimen the posterior 
portion of this bone is missing and its relationship to the ptery- 
goid can only be estimated. The palatine tooth is more laterally 
placed than its counterpart in Permian dissorophids. 

The vomers are not completely visible in any single fossil, 
but from the several specimens their configuration can be deter- 
mined. It is apparent that Steen's reconstruction of these bones 
places them too far posteriorly. In her specimen, the bones have 
either become disarticulated from the anterior margin of the 
skull, or the covering of denticulate "skin" has spread over the 
posterior margin making it appear that the bones extend into 
the interpterygoid vacuities. The relationship of the vomers can 
be seen in the type skull and in AMXIl 2566. One pair of 
prominent vomerine teeth is situated just medial to the anterior 
margin of the internal nares, but there is no sign of the second 
pair noted in Tersomiiis. The anterior region of the vomers is 
covered by denticulate "skin" in all specimens; thus the pres- 
ence or absence of an internarial pit cannot be determined 
definitely. An internarial pit has not been described in A. 
(jrandiceps. The configuration of the internal nares was deter- 
mined from AMNH 2566. Their position is similar to that in 
Tersomius, although they are somewhat narrower. What were 
described by Steen as internal nares must have been only a rent 
in the palatal "skin" since their position in her reconstruction 
is much closer to the margin of the vomers than in any other 
dissorophid. 



232 



BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 



The parasphenoid is most readily observed in the British 
Museum specimen; unfortunately, it has separated from the 
pterygoids, and the adjacent margins of both bones are missing. 
Probably the relationship of the bones is similar to that observed 
in Tcrsomius, in which the parasphenoid overlaps the posterior 
margin of the basipterygoid process of the pterygoid, and the 
pterygoid and basisphenoid are in contact but have not com- 
pletely fused. The position of the internal carotids is the same 





^^?fifet2iM^vtm#iM^^^^ 



Fig. 22. Amphihamus lyeUi. A, Eestoration of palate; B, Eestoration of 
lower jaw, based primarily on ?*ICZ 1277, ventral view; C, Lateral view; 
D, Medial view. X 1- 



CARROLL: DISSOROIMIID EVOLT'TION 238 

as in Tc7\^o))iius. The doi'sal I'xtciisions of llic i)ai'as])li('ii()i(l plate 
lateral to the braiiicase, seen in Permian dissoropliids, are not 
preserved in any of these specimens. The enltriform process is 
best viewed on tlie type. Its anterior extremity is expanded 
laterally where it is in contact with the vomei's. 

I\rar<;-inal teeth are present in MCZ 1277, in th(^ tyj)e, and 
in A^IXII 2566. Althongh the entire conii)h»ment is not ])resent 
in any of these specimens, the number and density in all parts 
of the upper jaw can be determined. Tlic numhci- of teeth is 
approximately the same in all of the specimens i-e^ardless of the 
size of the skull. There is room for 21 in each premaxilla and 55 
in each maxilla, compared with 13 and 34 respectively in Ter- 
soniius. They are the same size throughout the jaw ; in the larger 
specimens they reach a length of about 2 mm. In the reconstruc- 
tion (Fig. 22 A), the tooth replacement pattern in the right 
maxilla is based on MCZ 1277 ; the position of teeth and pits in 
the rest of the skull is arbitrary. 

The quadrate is slightly visible in MCZ 1277, but the recon- 
struction is based primarily on other dissoropliids. 

Only in the type specimen is the sphenethmoid visible. Al- 
though incomplete, it apparently resembled that bone in other 
dissorophids. Except for the occipital region in the type, the 
posterior portion of the brainease is not visible in any of the 
specimens. 

A layer of denticulate "skin" covered almost the entire palate 
in the living animal. Gaps were present for the reception of 
the palatine teeth, and in the region of the internal nares and 
adductor fenestrae, but most or all of the interpterygoid vacui- 
ties were covered. The denticles, particularly large in the region 
of the pterygoids, must have been of use in holding prey. It 
seems doubtful that such a thick layer of denticulate "skin" 
covered the palate in Permian dissorophids, which all have 
denticles growing from the bones themselves. It may, however, 
have covered the interpterygoid vacuities in these genera. 

The reconstruction of the palate (Fig. 22 A) is probably 
accurate in the representation of individual units; however, 
one entire specimen might have somewhat different relative 
dimensions, since specimens of several sizes were used in making 
this reconstruction. 

The lower jaws are restored primarily on the basis of MCZ 
1277. The general configuration of the jaws can only be ap- 
proximated since they were all somewhat crushed into the skull 
roof on the specimens studied. The only point of ditference 



234 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

from the customary rhachitomous pattern is the apparent unity 
of the angular and surangular. Not only is there no suture 
separating them, but even in the pattern of dermal sculpture 
they appear as one. This is probably a result of the age of 
the specimen since it is the largest of all known Pennsylvanian 
dissorophids. This suture is also difficult to find in some speci- 
mens of Tcrsomius. 

The features of the skull of A. lyelli generally resemble those 
of Tersomius and the other Permian dissorophids, except for 
the contact of the prefrontal and postfrontal above the orbit, 
and the greater density of marginal teeth (exceeded only by 
Co7ijunctio). The region of the skull roof posterior to the orbits 
is shorter relative to the anterior region of the skull than in 
advanced dissorophids, but similar to that of Tersomius and 
Amphihamiis grandiceps. 

The type specimen includes an almost complete skeleton, 
lacking only the tail and some of the fingers and toes. The 
specimen is preserved so that most of the right side is visible, 
with some features, however, present in a cast of the opposite 
side. 

Supplementary information is provided by USNM 4461 (Fig. 
24). This specimen unfortunately lacks the anterior end of 
the skeleton and the skull. Judging from the relative size of 
the skull and postcranial material of the type, this specimen 
must have had a skull about the size of MCZ 1277 or BM(NH) 
R.2670. 

There are 25 presacral vertebrae in the type specimen. The 
exact number (if there is a fixed number) is in dispute in 
A. grandiceps. Watson (1940) and Gregory (1950) agree that 
CNHM 2000 has 18; Gregory notes 21 in the type of Mazon- 
erpeton, which Moodie (1916) says has 27. The first two verte- 
brae are modified and might be called cervicals. The first lacks 
transverse processes and ribs, is much narrower than its fellows, 
and has special articulations with the occipital condyles and 
with the second vertebra. The exact nature of either of these 
articulations is uncertain. A single neural spine is visible ; 
whether a second was present as in Dissorophus (Williston, 
1910) cannot be determined. The spine is narrow, and appears 
slightly shorter than those of the remainder of the anterior 
vertebrae. The atlas does not overlap the second cervical to 
the extent seen in Dissorophus. The neural arch of the atlas is 
fused to the intercentrum. No separate pleurocentra are visible, 
and they too may be fused to the arch. No proatlas was seen. 



CARROT, L : DISSOKOIMl II) KVOIJ'TIOX 235 

The secoiul vortehi-a luis a slioi-f neural arcli, small transverse 
proeess(>s, and no ril)s. It articulates with the atlas by an ill- 
defined anterior extension above th(> neural canal. Its posterior 
zyp-apophyses are like those of the rest of the column. Between 
the second and third vertebrae there is a free iiitcrcentrum, but 
uo plenrocentra are visible. 

The ;?rd vertebra is similar to numbers 5 through 25 ; the 4th, 
however, is modified in having a shorter neural spine, eontribut- 
ing as in Eryops to greater ease in lifting the head. Vertebrae 
numbers 3, and 5 through 25, ai-e (|uite uniform and display 
the normal rhachitomous pattern. The neural spines are all 
short and unornamented. There is one sacral vertebra which 
bears a large sacral rib, as in Eryops and Dissorophus, but 
unlike the condition in Cacops. Five postsacral vertebrae are 
visible but are so badly crushed that just enough remains to 
show a general resemblance to the dorsals. 

The position and general configuration of the intereentra 
and plenrocentra are visible in numerous vertebrae, but no 
thorough description is possible since they are always somewhat 
obscured by the remainder of the vertebrae, the ribs and matrix. 

Ribs are present on all the vertebrae behind the cervicals. 
There may have been a small rib on the second vertebra, which 
bears a reduced transverse process, but none is visible. Dissorn- 
phus angnstus has no rib in this position; the condition in 
.1. (jrandiceps cannot be ascertained. The first three ribs are 
the longest (5 mm) and have widely expanded, overlapping 
ends. The fourth and fifth ribs are transitional, while the rest 
of the column bears ribs without distal expansions. Behind 
the shoulder region the ribs become shorter, having a length 
of only 3 mm just anterior to the sacrum. The ribs of the 
first two postsacral vertebrae are about this same length. The 
next two ribs are longer and the last visible one is very short. 
None was seen on the 32nd vertebra, but exact determination 
was difficult due to its crushed condition. The posterior ribs 
are much better preserved in HSNM 4461 than they are in the 
type. Dorsally, presacral ribs 12 through 18 appear as straight 
rods, terminating in the tubereulum. Ventrally, the ])roximal 
half of the rod has a slender flange which terminates at the 
capitulum. The tubereulum and capitulum extend dorsally and 
ventralh' from the body of the rib but aj)parently remain 
connected. Near the sacrum the ribs do not bear this ventral 
flange so that the two heads together form a greatly expanded 
portion at the immediatelj^ proximal end. The two heads are 



236 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 




X 



CARROLL: DISSOROPIIID EVOLUTION 237 

partially separated hy a fjroove on the rear surfaee of the rib. 
Tlie anterior surface is not visible. 

The anterior ribs articulate -with both tlu» transvei-se process 
and the intercentnini, althoufrh the latter element does not 
have a particular area for its attachment as it does in Cacops. 
The ribs in the mid-portion of the column probably did not 
articulate with the intercentrum. 

Both sacral ribs are preserved in the type ; the left is visible 
from the medial surface affixed to the left ilium. The right 
is seen in lateral view, having ])artially separated from the right 
ilium. Each sacral rib includes a transverse l)ar articulating 
with a large transverse process of the sacral vertebra. This bar 
bends sharply caudad after contact is made with the ilium. It 
is not possible to determine the exact extent of the blade of 
the rib. The right appears similar to that of Broiliellus hrevis, 
while the left appears more extensive, similar to that of Bis- 
sorophns multicinctiis. Neither of the adjacent ribs is at all 
involved in the sacrum. 

The pectoral girdle is essentially complete, although somewhat 
disarticulated. Its structure conforms to the general rhachi- 
tomous pattern. The scapulocoracoid plate is complete except 
for the glenoid region, which is obscured by the humerus. It 
is proportionately wider (or shorter) than that of Eryops. 
The scapulocoracoid plate compares very well with that of 
Amphihamus grandiceps. The cleithrum, as in that species, is 
restricted to the upper margin of the front of the scapula ; 
there is little dorsal expansion, such as is visible in Eryops, 
and the stem is quite short. The stem of the clavicle extends 
further dorsally than it does in Eryops. The ornamented ventral 
extension of the clavicle articulates with the interclavicle. The 
latter bone can be seen only in dorsal view, partially concealed 
beneath the left coracoid. Its exact nature cannot be determined, 
but apparently it was similar to the interclavicle of Ampliihanius 
grandiceps. The left scapulocoracoid can be seen from the in- 
side, but it is covered by the vertebral column so that no details 
are visible. The position of the pectoral girdle along the verte- 
bral column shown in Figure 25 is only approximate, based on 
the condition in Eryops and Cacops. 

The humerus is longer, relative to the length of the vertebral 
column, than in either Eryops or A. grandiceps, having a con- 
siderable shaft between ends expanded at right angles to each 
other. The ectepicondyle and entepicondyle are visible on either 
side of the ulnar articulation. The position of the limbs prevents 



238 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

checking the presence of the pectoral process which was noted 
in A. grandicrps by Gregory. The limbs are turned so that the 
proximal expansion can only be seen on edge, hence its extent 
cannot be stated. 

The ulna and radius are considerably shorter than the 
humerus. The ulna is best preserved on the right side ; it is 
in place and the olecranon extends around the end of the 
humerus as a triangular process. The radius is slightly shorter 
than the ulna and expanded distally. 

There are no ossifications in the region of the carpals. 

All four digits of the left manus are well preserved, lacking 
only the distal phalanx of the lateral digit. The metacarpals 
are about one-half the length of the radius ; the medial is the 
shortest and the next to medial, the longest. The proximal 
phalanges are about the length of the metacarpals ; the distal 
ones are half that size and bluntly pointed. From the propor- 
tions of the remainder of the hand, one and only one phalanx 
can be added to the last digit. The phalangeal count is the 
same as in A. grandiceps : 2, 2, 3, 3. As in A. grandiceps, the 
third digit is the longest — somewhat longer than the humerus. 
The length of the digits and their compact form in the fossil 
suggests that webbing may have been present. 

The dorsal portion of the pelvic girdle is clearly exposed. The 
lateral surface of the right half is visible, while the left shows 
its medial surface, partially covered by the right. As well as 
can be judged, each half is completely ossified, with no sign of 
sutures separating the individual bones. The most striking 
feature of the pelvis is the height of the ilium — quite similar 
to that of Eryops. On the lower portion of the posterior margin 
there is an indentation, below which is the ischium. Above this 
notch is a rugosity for a large muscle insertion. A small eleva- 
tion is visible in this area in Eryops, and a large rugosity in 
Dissorophus. The ischium extends a considerable distance 
posteriorly. The puboischiadic plate is mostly missing and with 
it the bottom of the acetabulum and the ischiadic prominence. 
A well ossified pubis extends anteriorly. The anterior margin 
of the acetabulum is similar to that of Eryops. Dorsally there 
is a large central recess, the supra-acetabular notch. In general, 
the pelvis resembles that of Eryops more than it does the later 
dissorophids. 

The pelvis of USNM 4461 is essentially the same shape as 
that of the type, again lacking the bottom of the puboischiadic 



CARROLL: DISSOROPHID EVOLUTION' 



239 



plato. p]iiongh of this is present, liowever, to indicate tlie pres- 
ence of a small ischiadic prominence almost directly beneath 
the supra-acetabular prominence. The latter has the same posi- 
tion and configuration as it does in the type. The ilium differs 
from that of the type in being relatively shortei-. 'riie ischium 
is apparently broken at the rear. 








Fig. 24. Amphibamvs hjelli. USNM 4461. X 1. 



Neither of the femora in the type is well preserved and both 
are turned at angles, obscuring the features most suitable for 
comparison with other dissorophids. Their most notable charac- 
teristic is their great length and lack of girth. The left femur 
is exposed in dorsal view, and both ends are crushed, obscuring 
any possible definitive features. From the rear an adductor 
crest is Adsible, but not sufficiently for description. The right 
femur can be seen in ventral view, showing a narrow adductor 
crest on the anterior, proximal margin. Both the proximal and 
distal ends are expanded, less so than in the Permian dis- 
sorophids, but with the same general configuration. 

The femur of USNM 4461 is preserved in rear view, allowing 
observation of the adductor crest not possible in the type. The 
crest is restricted to the proximal half of the bone. It expands 
from the middle to within a millimeter or so of the proximal 
end, at which point it descends toward the articular surface. 
The dorsal surface of the femur is more concave, as viewed 
laterally, than that of any later dissorophids. Tiiere is an 



240 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

obvious surface for articulation with the fibula. The dorsal 
depression and the shape of the adductor crest are very similar 
to those observed in Arkanserpeton. 

The fibula of the type is thinner and just slio-htly longer than 
the tibia. In Eryops the tibia is markedly longer, in Cacops 
slightly longer. The proximal expansions of the bones are about 
equal, while the distal expansion of the tibia is slightly larger 
than that of the fibula. The tarsals consist of five patches of 
cartilage. 

The foot can be almost completely reconstructed from AMNH 
6841. Of the five digits, only the distal phalanges of the lateral 
two are missing. The metatarsals are about one-half the length 
of the tibia ; the medial one is the shortest ; the remainder are 
all of approximately the same length. The proximal phalanges 
are all about the length of their metatarsals. The distal 
phalanges, like those of the hand, are half the length of the 
proximals and bluntly pointed. The second and third digits are 
the longest, both exceeding the length of the femur. As in the 
hand, webbing seems probable. The phalangeal count is : 2, 2, 
3, 3, 3. 

Habits: The general configuration of the skeleton indicates 
an active animal. Ossification is complete except for the carpal s 
and tarsals, and the limbs are long relative to the length of 
the body. The lack of prominent tuberosities on the limbs, 
expected in an animal of small size, indicates that even the 
largest of these animals was not heavily built. An interesting 
feature is the length of the hands and feet, much in excess of 
those of any Permian dissorophids. Apparently this was an 
adaptation for a coal swamp environment. Little modification 
in this regard is noted in other portions of the animal's anatomy, 
however. The great length of the limbs, absence of lateral line 
canals, and the lack of a highly developed dermal shoulder 
girdle — associated in other forms with aquatic existence (Wat- 
son, 1919) — suggests that Ampliihamus lyelli did not habitually 




Fig. 25. Amyhihamm lyelli. Restoration of skeleton. X -/3- 



CARROLL: DISSOKOIMIID EVOIvlTIO.V 241 

livo ill the water. Supjiortiiij'' tliis is the almost coiriplote ossifica- 
tion of the skeleton and the ver^- well developed sacral attach- 
ment. The lonfr, and perhaps webl)ed, feet would have allowed 
it to traverse readily bogs and shallow pools. As a response 
to increased aridity, its Permian descendants coiii})letely lost 
this adaptatioiL 

Ampiiibamits calliprepes (Steen) 

Mordcx calliprepes Steen, 1938, p. 260. 

r have not been able to investijjate personally any of the 
Nyfany material of possible dissorophid affinities. Nevertheless, 
the additional knowdedg'e we now have concerning other Penn- 
sjdvanian species makes it necessary to comment further on 
those previously described. Three forms from Nyrany were 
considered by Gregory (1950) to be dissorophids. One is 
Bicnndon Hninophyes. It is very difficult to conceive of this 
animal as even a member of the Rhachitomi, much less of the 
Dissorophidae. The structure of the palate is particularly diffi- 
cult to reconcile. The shapes of the parasphenoid and pterygoids 
are vastly different from those of any dissorophid. The ptery- 
goid, ectopterygoid and palatine all bear numerous large teeth 
not encountered in dissorophids. The orbits are separated by 
far too great a distance relative to their size for any known 
dissorophid. the pattern of sculpturing is different from that 
of any mem])ers of that family, and the tabular-supratemporal 
appears as a single bone rather than as separate units. Romer 
(1950) placed Ricnodon among the lepospondyls. 

Gregory's inclusion of Mordex calliprepes (Steen, 1938) 
among the dissorophids is entirely justified. In fact, there is 
yery little to separate this species from Ampliibamus lyeUi on 
the evidence of the skull roof and palate. The specimen on 
which this species is based is just slightly smaller than the 
British Museum specimen of A. lijelli, so comparison will be 
made with that form. The differences are primarily in propor- 
tion. In "Mordex/' the width across the back of the skull 
table is small compared with the length of the skull, the contact 
of pre- and postfrontal is larger than in A. lyelli, and the post- 
parietals are narrower. When comparison is extended to the 
type of A. lyelli, it becomes apparent that the dimensions of 
"Mordex" are probably within the range of variation of that 
species. All the proportional differences, hoAvever, suggest a 
position slightly closer to A. grandiceps. For this reason, as 



242 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

well as the geographical separation of this form, it seems 
reasonable to maintain it as a distinct species, at least until 
more is known of the anatomy. There is one additional point 
of distinction. According to Steen (1938, p. 260), "there is 
a small pentagonal interfrontal bone present, which, unlike the 
other dermal bones, is unornamented." It seems possible that 
this may be only an artifact, especially since it is unsculptured. 

Romer (1947) suggested "Mordc.r" as a possible ancestor 
of the trematopsids. While there is nothing to definitely bar 
it from such a position, it is certainly no closer to that family 
than any of the other Pennsylvanian dissorophids. It also has 
a large number of features that separate it from the known 
Permian trematopsids. The frontals do not extend in front 
of the orbits to the extent that they do in the Trematopsidae. 
The skull is not elongated in front of the orbits. The post- 
parietals are quite small, as is the rear skull table. There is 
no apparent modification of the external nares. 

Another form mentioned by Gregory as a dissorophid is a 
specimen of Limnerpeton laticeps (Fritsch, 1883, plate 36, 
fig. 1). The immaturity of the specimen prevents any conclusive 
statement. 

Amphibamus grandiceps Cope 

This species was discussed quite thoroughly hy Watson (1940) 
and l)y Gregory (1950), but in light of the evidence reported 
here, it is profitable to review certain features of its anatomy. 
The most important thing to keep in mind concerning the 
species is the small size and youth of all known specimens. The 
skull has many features peculiar to young individuals. Among 
these are the large size of the orbits, pineal foramen, and 
external nares, the tendencj?^ of the bones to separate, and the 
simplicity of suture lines. 

One peculiarity that is not explained in this way is the lack 
of a suture between the supratemporal and the tabular. Ap- 
parently this is lacking on both of the extant specimens. 
Descriptions of two missing specimens, however, do indicate 
such a suture (Moodie, 1916, p. 128, fig. 26; and Hay, 1900, 
p. 122). It is almost certain from phylogenetic considerations 
that the tabular must have been a separate unit as it is in 
most of the Rhachitomi. 

On two other points, changes might be made in recent de- 
scriptions. In the neotype, contrary to ({regory's interpreta- 
tion, tlie jugal and lacrimal do ai)pear to meet lieiicath the 



CARROI.I, : DISSOROI'IIID KVOLT'TIOX 248 

orbit, (>v('i! if (iiily with a very small coiitacl. In Watson's 
(Inscription of the Chica^-o specimen he mentioned the existence 
of a patch of scale-covered skin wliicli lay between the upper 
and lower jaws on the left side of the skull in al)out the same 
area as an oi-liit. lie dismissed the idea that this was an ossifica- 
tion in the upi)(>r eyelid. In view of the condition in A)uphi- 
hainus hiilli and particulai-ly in Tcrsoniius, it a{)pears tliat this 
is just what it is, rather tlian part of a covering between the 
lower jaws. 

Some of the features reported in earlier descriptions of 
Amphil)(imu>< (/rand ice ps would separate it distinctly from 
Auiphihfniuis Ii/elli. Several of these features were only inferred, 
however, and so may be ignored until they can be checked 
in moi'e adequately preserved material. Whether there are 
ribs on the first, second and third vertebrae, as well as aliead 
of and behind the sacral rib, cannot be determined. CNIIM 
2()()(), on which most of the details of Watson's description were 
based, consists of molds of both sides of the bones, with the 
bone itself preserved only as a white film which has for the 
most part been removcMl. In preservation of this kind it is 
difficult to tell sutures from cracks, and irregularities in the 
matrix from features of the skull. There is nothing in either 
this skull or YPM 794 to determine the existence of the peculiar 
upper jaw joint described by Watson, or the unusual septo- 
maxilla. A row of palatal teeth such as reported by Watson 
would be a decidedly unusual character for a dissorophid, and 
apparently consists of bases of teeth from the broken upper 
jaw, the ends of these teeth having remained in place in the 
maxilla to be preserved alongside their own roots. 

As Watson stated, there is no sign of paired teeth on the 
vomers, palatines and ectopterygoids ; they are apparently cov- 
ered either by the lower jaws or by a layer of denticulate "skin" 
such as is present in A. lyrlli. They may even be absent in 
such a young animal. 

Despite the youth of these specimens, several features defi- 
nitely distinguish them from A. lyelli. The number of marginal 
teeth is different in the two species but is relatively constant 
within the mend)ers of each. A. grandiceps has about 48 
marginal teeth, while .1. hjelli has about 76, regardless of 
the size of the skull. The number of presacral vertebrae appears 
to be less in A. grandiceps, but there is such a disparity in 
published counts for that species that no definite statement can 
be made. There are also changes in relative dimensions that 



244 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

may hold true for adult specimens of A. grandiceps. The pre- 
and postfrontals have a broader line of contact in that species 
than in A. lyelli, and the postparietals are smaller. A feature 
in which A. grandiceps differs from later dissorophids is the 
perforation of the stapes. In this species there is a definite hole 
near the base, while in Broiliellus and Dissorophus it is im- 
perforate ; the condition is not known in A. lyelli or in Ter- 
som.ius. 

Arkanserpeton arcuatum Lane 

An isolated femur was described by Lane (1932) from the 
Paris shale of Kansas, roughly equivalent to the McAlester 
shale, at the top of the Pottsville or the base of the Allegheny. 
He considered that it was an embolomere, but as Romer (1947) 
has pointed out, it is probably a dissorophid. It is larger than, 
although otherwise similar to, the femur of Amphihamns lyelli. 
None of the femora of Pennsylvanian dissorophids is well 
enough preserved to determine specific relationships. 

Interrelationships of the Pennsylvanian Dissorophids 

Compared with the Permian dissorophids, the Pennsylvanian 
members of the family are few and apparently little diversified. 
Despite the long time span during which dissorophids are 
known in the Pennsylvanian, there are at most two genera 
represented, compared with at least six genera in the Wichita 
group alone of the Lower Permian. This might be considered 
only a result of the general paucity of Pennsylvanian deposits 
were it not for the fact that the genus Amphihamus is known 
from three deposits of differing age and locality. This suggests 
that there was truly little diversity of the family in the Penn- 
sylvanian. 

The relationships among the three species of Amphihamus 
cannot be determined definitely, since A. grandiceps is repre- 
sented only by very young specimens and A. calliprepes is 
known only from an incomplete skull table. All three may 
have developed from a common ancestor, or A. grandiceps may 
have given rise to the other two species. Nothing can be stated 
concerning the relationships of Arkanserpeton until more ma- 
terial is available. 

Tersomius almost certainly evolved from Amphihamns, but 
it is not known from which species. It is probable that the 
remainder of the dissorophids evolved from Tersomius rather 



CARROLL: niSSOROIMIin KVOLfTIOX 245 

tliaii (lii'cctly from Ainpliih(n)ii(s since Tcrscnnius lias several 
features of the hio-hei- dissoropliids not yet acquired by Aynphi- 
hamua, such as the eiilraiici* of the fi'outal into the margin of 
the ()i'])it, a well d(n-elo|)e(l intei-iiarial ])it. and a reduced tooth 
count. It should be noted, ho^vever, that 1\ rso})iius shares most 
of its primitive features -with A)np]iihaiuus and essentially 
represents a contiiuiation of a line of evolution established in 
the early PennsylvaniaiL 

The critical point in the evolution of the Dissorophidae 
occurred when the <iroup became armored. The unarmored 
genus Tersoini.HS carried on throughout the AA^ichita group the 
general trends suggested by Amphihanius in the Pennsylvania n, 
but apparently did not produce any further lines of evolution 
after giving rise to the armored genera early in the Permian. 
The remainder of the family, in contrast, diflPerentiated rapidly 
once armor became established. 

RELATIONSHIPS OF THE DISSOPvOPIIIDAE 
AMONG THE RIIACHITOMI 

The dissorophids can be traced back to the Middle or possibly 
Lower Allegheny. There is only one family to which the dis- 
sorophids are definitely known to be related — the Zatrachyidae. 
As was pointed out by Steen (1931), very few features separate 
Stcgops, the earliest zatrachyid, from "PJatyrJiivopf;" = Amphi- 
hamus lyclli. Although some features appear to bar Stegops 
from a position of direct ancestry of the Permian zatrachyids 
(Langston, 1953), there is little doubt that this genus is closely 
related to the other members of the family. 

All of the other families of the Eryopsoidea have been 
thought to be closely related to the dissorophids (Olson, 1941; 
Romer, 1947; and Moustafa, 1955), but as .yet no forms have 
been described that are in any way intermediate between these 
families and the Dissorophidae. Nor can any direct relation- 
ships be found between any of the other rhachitomous groups 
and the dissorophids. As was pointed out by Romer (1947), 
most of the features of cranial anatomy point to a common 
origin for the Eryopsoidea. He did not, however, rule out the 
possibility that these features might have been achieved sepa- 
rately by the several families in that group. 

Until more is known of early Pennsylvanian amphibians, it 
is not possible to determine either the ancestry or relationships 
of the earliest dissorophids. 



246 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 





Europeon stages 


American series 














< 

tr 

Ll) 
Q_ 


Tartarian 


Ochoan 




Guodalupian 




Texas section 






Group 


F ormat ion 




Ka zanian 
- " ~ "u f 1 m 1 a n 


Pease River 




Blame 


Flowerpot 








Kungunan 


Leonordian 


Clear Fork 


Choza 


Vale 


Artinskian 


Arroyo 


Wichita 


Lueders 


Clyde 


Belle Plains 


Sakmonan 


W o 1 f c m p 1 a n 


Adnniral 


Putnam 


Moron 


Pueblo 


Z 
< 

z 
< 

> 

z 
z 

LU 
CL 


St ephanian 


Monongohela 


1 1 N y ra ny 
= Linton 

= Mozon Creek 


Conemaugh 


Westphalian 


D 


Allegheny 


C 






Pons sh 


B 


Pottsville 




A 


No muna n 


















1 



Fig. 26. Peimsylvanian and Permian stratigrapliy. The chart is liased 
primarily on Dunbar and others (1960), and ]\Ioore and others (194-i). 
Correlation of loealities follows Eomer (1947 and 1958), and Panchen 
and Walker (1960). 



CAKKOLL: DISSOROI'IIID EVOLUTION' 



247 



ABBREVIATIONS 



a 
ar 

asc 



clci 

CO 
CO I 
CO II 

cof 

d 

e 

ee 

eo 

ext 

f 

fa 

fo 

fv 

gf 

li 

ic 

icf 

icg 

icl 

icp 

il 

inif 

ilia 

iiip 

int 

is 

J 

1 

m 

nif 

mrf 

n 

nac 

iicli 
111 





articular 

ascending process of 

epiptorygoid 
position of liasioccii)ital 
hasisiilicnoid 
clavick' 
cleitlirnin 
coroiioid 
iiitercoronoid 
precoronoid 
coracoid foramen 
dentary 
epipterygoid 
eetopterygoid 
exoeeipital 

armor, external series 
frontal 

foramen for artery 
fenestra oralis 
foramen for vein 
glenoid foramen 
humerus 
intercentrum 
internal carotid foramen 
internal carotid groove 
interclavicle 

internal carotid passage 
ilium 

inframeckelian fossa 
interna sal 
internarial pit 
armor, internal series 
ischium 
jugal 
lacrimal 
maxilla 

mandibular foramen 
median rostral fontanel 
nasal 
space for cartilaginous 

nasal capsule 
position of notochord 
nasolacrimal groove 
otic capsule 



ol.f 


oliturator foranuMi 


p 


parietal 


pa 


prearticular 


].(• 


pleurocentrnm 


I'f 


postfrontal 


I'l 


palatine 


pm 


premaxilla 


po 


])ostorl)ital 


pos 


postsplenial 


pp 


postparietal 


ppc 


palpebral cup 


prf 


prefrontal 


pro 


l)ro()tic jjrocess of 




epipterygoid 


ps 


para sphenoid 


pt 


pterygoid 


ptf 


posttemporal fossa 


pu 


pubis 


q 


quadrate 


q.i 


quadratojugal 


r 


rib 


ra 


radius 


rem 


recess for rectus eye 




muscles 


sa 


surangular 


sc 


scapulocoraeoid 


scl 


sclerotic plates 


se 


sphenethmoid 


set 


position of sella turcica 


sgf 


supraglenoid foramen 


sni 


septomaxilla 


soc 


supraoccipital 


sp 


splenial 


sq 


squamosal 


sr 


sacral rib 


St 


supratemporal 


sta 


supraorbital branch of 




stapedial artery 


stp 


stapes 


t 


tabular 


u 


ulna 


\' 


vomer 


vcl 


vena capita lateralis 


I-XII 


foramina for cranial 




nerves 



248 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

LITERATURE CITED 

Broili, F. 

1904. Pcrmische Stegoeephalen und Reptilien aus Texas. Palaeonto- 
graphica, vol. 51. pp. l-±9, 51-120. 
Bystrow, a. p. 

1935. Morphologisclie Untersuchungen der Deekknocken des Scliadels 
der Wirbeltiere. 1. Mitteiluiig. Sehiidel der Stegoeephalen. Acta 
Zool., vol. 16, pp. 65-141. 
Case, E. C. 

1910. New and little known reptiles and ampliiliians from the Per- 
mian(?) of Texas. Bull. Amer. Mus. Nat. Hist., vol. 28, pp. 
163-181. 

1911. Revision of the Amphibia and Pisces of the Permian of North 
America. Publ. Carnegie Inst. Washington, no. 146, pp. 1-179. 

Case, E. C, S. W. "Williston, and M. G. Mehl 

1913. Permo-Carboniferous vertebrates from New Mexico. Publ. 
Carnegie Inst. Washington, no. 181, pp. 1-81. 
Cope, E. D. 

1868. Synopsis of the extinct Batrachia of North America. Proc. 
Acad. Nat. Sci. Philadelphia, 1868, pp. 208-221. 

1874. Supplement to the extinct Batrachia and Reptilia of North 
America. I. Catalogue of the air-breathing Vertebrata from 

the Coal Measures of Linton, Ohio. Trans. Amer. Philos. Soc, 
vol. 15. pp. 261-278. 

1875. The extinct Batrachia of Ohio. Proc. Acad. Nat. Sci. Phila- 
delphia, 1875, p. 16. 

1895. A batrachian armadillo. Amer. Naturalist, vol. 29, p. 998. 
DeMar, R. 

1961. A review of the family Dissorophidae (amphibians) with em- 
phasis on the late Wichita and Clear Fork genera. Unpublished 
Ph.D. dissertation, Dept. of Geology, University of Chicago. 
Dunbar, C. 0., and others 

1960. Correlation of the Permian formations of North America. Bull. 
Geol. Soc. Amer., vol. 71. pp. 1763-1806. 
Fritsch, a. 

1883. Fauna der Gaskohle und der Kalksteine der Permformation 
Bohmens. 4 vols. Prague. (1879-1901.) 
Gaupp, E. 

1900. Das Chondrocranium von Laeerta agilis. Ein Beitrag zum Ver- 
standnis des Amniotenschadels. Anat. Hefte, vol. 15, pp. 433- 
596. 
Gregory, J. T. 

1950. Tetrapods of the Pennsylvanian nodules from Mazon Creek, 
Illinois. Amer. Jour. Sci., vol. 248. pp. 833-873. 
Hay, O. p. 

1900. Descriptions of some vertebrates of the Carboniferous age. Proc. 
Amer. Philos. Soc, vol. 39, pp. 96-123. 



CAHHoi.i, : i)iss(»i{()i'iiii) i;v()i,r'n()\ 'J4M 

Laxe, it. II. 

nC'.L'. A new stegofeplialian from tlic Pi'niisylv:iiii;iii of Arkjinsas. 
Kansas Univ. Rci. Hull., vol. 20. vi>. :',!?, :',\7. 
Laxgstox, W. 

1053. Perniiaii aiiipliiliiaiis from Nrw .Mexico. Univ. Calif. PiiM. 
Gool. Sci., vol. 29, no. 7, i)p. :{49-41(). 
.MuuDiK, K. L. 

1909. Carboniferous air lucatliiiiii vcitclnatcs of Hm' Cnitcd States 

National Museum, i'roc V. S. X;tt. Mus., vol. 37, pp. 11-28. 
]91(i. The Coal treasures AiiipliiMa of North AiiuTica. I'liM. Cariie- 
ii'ic Inst. Washington, no. 238, ]>\k 1-222. 
M(ioi;i:, li. ( '., ami others 

19-1-4. Correlation of Pennsylvaniaii formations of North America. 
Bull. Geol. Soc. Amer., vol. 55, pp. G57-70(i. 

MOUSTAFA, Y. SHAWKI 

1955. The affinities of Parioxjis frrricoliis and the ])hyio<reny of the 
"Eryopsoid" ami)hiliiaiis. Hull. Inst. E^ypte, vol. 3G, pp. 77- 
104. 
Olson, E. C. 

I!i41. The family Treinatopsidae. .lour, (ii'ol., vol. 49, no. 2, ]>]>. 149- 
176. 
Paxchex, a. L., and A. D. Walker 

1960. British Coal Measure laliyrinthodont localities. Ann. .Mag. Nat. 
Hist., ser. i;!, vol. 3, no. ;!ii, pp. ?,21-332. 

ROMER, A. S. 

1930. The Pennsylvaiiian tetiajxids of Linton, Ohio. Hull. Amer. Mus. 
Nat. Hist., vol. 59. pp. 77-147. 

1947. Review of the Laliyrinthodontia. Bull. .Mus. Comi). Zool., vol. 

99, pp. 1-368. 
Ht'iO. The nature and relationships of the Paleozoic microsaurs. Amer. 

.Tour. Sci., vol. 248, pp. 628-654. 
19.j8. The Texas Permian redbeds and their vertebrate fauna. In: 
Studies on fossil vertebrates, edited by T. S. Westoll. London, 
pp. 157-179. 
RoMER, A. S., and T. Edixger 

1942. Endocranial casts and brains of living and fossil Amphibia. 
Jour. Comp. Neur., vol. 77, no. 2, pp. 355-389. 
Sawix, H. J. 

1941. The cranial anatomy of Eryops megacephalus. Bull. Mus. 
Comp. Zool., vol. 86, pp. 407-463. 
Steex, M. 

1931. The British Museum collection of Amphibia from the Middle 
Coal Measures of Linton, Ohio. Proc. Zool. Soc. London, 1930 
(1931), pp. 849-891. 

1938. On the fossil Amphibia from the Gas Coal of Nyi-any and 
other deposits in Czechoslovakia. Proc. Zool. Soc. London, 
(B), vol. 108, pp. 205-283. 



250 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

SUSHKIN, P. P. 

1927. Oil the modifications of the niaiidiltular and hyoid arches and 
their relations to the braincase in the early Tetrapoda. Palaeont. 
Zeitschr., vol. 8, pp. 263-321. 
Watson, D. M. S. 

1919. The structure, evolution and origin of the Amphibia. — The 
"orders" Eachitomi and Stereospondyli. Philos. Trans. Eoy. 
Soc. London, (B), vol. 209, pp. 1-73. 
1940. The origin of frogs. Trans. Roy. Soe. Edinburgh, vol. 60, pp. 
195-231. 

WiLLISTON, S. W. 

1910. Cacops, Desmospondylns: new genera of Permian vertelirates. 
Bull. Geol. Soc. Amer., vol. 21, pp. 249-284. 

1911. American Permian vertebrates. Chicago, 145 pp. 

1914. Broilielliis, a new genus of amphibians from the Permian of 

Texas. Jour. Geol., vol. 22, pp. 49-56. 
Wyman, J. 

1858. On some remains of batrachiaii reptiles discovered in the coal 

formation of Ohio, by Dr. J. S. Newberry and C. M. Wlicatley. 

Amer. Jour. Sci., ser. 2, vol. 25, pp. 158-163. 

Eeceived Decemljer 15, 1962. 



PLATES 



BULLETIN : MUSEr:M OF COMPARATIVE ZOOLOGY 




i 



Plate 1. Range of variation in " Aspidosaurus" armor. ^ICZ Hi 
Rattlesnake Canyon, Admiral Formation. X !• 



('AR1{()I.I,: DISSOHOIMIII) KVoLrTIOX 




I'LATE 2. Ampliihiniiiis lijdii. AMMl (i841, Linton, Ohio. X 1- 



Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. V.U, No. 8 



THE GENUS MIC RATHE N A (ARANEAE, ARANEIDAE) 
IN THE WEST INDIES 



By Arthur M. Chickering 



CAMBRIDGE, MASS., U.S.A. 
1' R I N T E D FOR THE MUSEUM 

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Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. 131, No. 8 



THE GENUS MICR ATHENA (ARANEAE, ARANEIDAE) 
IN THE WEST INDIES 



By Arthur M. Cpiickering 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

June, 1964 



Bull. -Mus. Comp. Zool., Harvard Univ., 131(8): 251-281, June, 19G4 

No. 8 — The Getvis Micrafhcna (Araneae, Arancidae) 
in the West Indies 

By Arthur M. Chickering 

In connection with my study of the genus Micrathena in Central 
America (1961) and South America (1960a, b, c), I have recently 
had the opportunity to study all specimens of the genus from the 
West Indies now in the collections of the Museum of Comparative 
Zoology at Harvard College. During the summer of 1958 I had the 
privilege of studying the West Indian specimens of Micrathena in 
the extensive collections of the British Museum (Natural His- 
tory) ; the collections of the American Museum of Natural History 
have also been made available to me. As a result of my study I 
have found what I believe to be serious confusion in the identifica- 
tion of certain species native to the West Indies. It is also obvious 
that errors of synonymy have been made. I hope this paper will 
contribute to clarification of the difficulties. 

I believe there is urgent need for some competent worker to 
study the whole genus for the entire Western Hemisphere with the 
intention of publishing a complete revision of the genus that would 
serve for many years, as Rcimoser's (1917) work did for a genera- 
tion. This extensive piece of work should be preceded by intensive 
collecting in the West Indies and, especially, in the tropical regions 
of South America. I am convinced that such field work would yield 
excellent results. Not only would new and interesting species be 
found but much progress could be made in the now difficult prob- 
lem of correctly matching up the sexes. 

Acknowledgments extended and appreciation expressed in recent 
published papers (Chickering, 1960a, b, c, and 1961) are here re- 
l)eated with my personal gratitude for encouragement over many 
years. I also wish at this time to express my gratitude and appre- 
ciation to Dr. W. J. Gertsch, American IMuseum of Natural His- 
tory, for the loan of a valuable collection. 

Holotypes of M. levii, M. gertschi, and M. practcrlta will l)e de- 
posited in the American Museum of Natural History, New York 
City. Holotypes of all other new species will be deposited in the 
Museum of Comparative Zoology, Harvard University. 

Micrathena Sundevall, 1833 

Type species, M. clypeata (Walckenaer, 1806), designated l)y 
Simon, 1895:859. 



254 



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MiCRATHENA BRYANTAE sp. nOV. 

Figures 1-3 

Note: Miss Bryant (1940) described briefly a single male from 
Cuba, but she did not give a specific name to it. I propose regard- 
ing it as the holotype of a new species and posthumously honoring 
its discoverer in its specific name. 

Male holotype. Total length 4.4 mm. Carapace 1.76 mm long; 
1.17 mm wide opposite posterior border of second coxae where it is 
widest; 0.59 mm tall at region of central fovea, which is a well 
marked circular pit; gently arched from PME to posterior de- 
clivity, with a pair of distinct dorsolateral foveae in the cephalo- 
thoracic groove. 

Eyes. Ocular tubercles moderately well developed. Viewed 
from above, both eye rows moderately recurved; viewed from in 
front, anterior row gently recurved, posterior row definitely pro- 
curved, all measured from center. Central ocular quadrangle wider 
behind than in front in ratio of 21 : 19, slightly wider behind than 
long. Ratio of eyes AME:ALE:PME:PLE "= 7:6.5:10:6 (long 
diameter used where differences exist) . AME separated from one 
another by a little less than their diameter, from ALE by three 
times their diameter. PME separated from one another by about 
three-fifths of their diameter, from PLE by two and one-fifth 



External Anatomy of Micmlhena 
Figures 1-3, M. bryantae 




Fi^.s. 1-2. Two views of the left italpal tarsus, tibia iind jiatella. 
Fig. 3. Nearly dorsal view of base of left pali'al rvnil)ium with basal 
tarsal hook, tibia and patella, more enlarged. 



c;iii(Ki;i{i.\(;: micrathena in thp: west indies 255 

times their diameter. Laterals separated IVom one another by 
slightly less than one-third of the diameter of PLE. Height of 
clypeus equal to twelve-sevenths of the diameter of AME. 

Chelicerae. Fairly robust; basal segment about 0.54 mm long; 
teeth along fang groove not observed because^ of fi'agility of tlu; 
holotype. 

Sternum. Scutiform in general; tubercles barely indicated; 
continued laterally between coxae and posteriorly between fourth 
coxae as slender sclerites ; fourth coxae barely separated ; surface 
very finely rugulose. 

Leg.s. 4123. Width of first patella at "knee"^ 0.16 mm, tibial 
index of first leg 11. Width of fourth patella at knee 0.15 mm, tibial 
index of fourth leg 11. 

Femora Patellae Tibiae Metatarsi Tarsi Totals 

(All measurements in millimeters) 



I. 


1.43 


0.50 


0.91 


0.99 


0.52 


4.35 


II. 


1.37 


0.49 


0.78 


0.85 


0.48 


3.97 


III. 


0.85 


0.29 


0.49 


0.52 


0.36 


2.51 


IV. 


1.76 


0.36 


0.98 


1.07 


0.49 


4.66 


Palpus 


0.33 


0.12 


0.15 




0.66 


1.26 



Legs with few spines; these mostly broken off from handling. 
Hook on first coxa and corresponding ridge and groove on second 
femur lacking. 

Palpus. See iVIiss Bryant's figure 143 (1940) for one view ol the 
palpal tarsus and til)ia, and Figures 1-3 in this j^aper for other 
views. 

Abdomen. Length 2.73 mm; nearly rectangular in dorsal view 
(Miss Bryant's fig. 139) ; only moderately flattened; very little, if 
any, indication of suppressed spines. 

Color in alcohol. See Miss Bryant's description (1940) . 

Type locality. The male holotype is from Cuba, Oriente, Los 
Llanos, 1000-2000 ft. elevation, July 16-20, 1936 (P. J. Darling- 
ton, Jr.). 

Other records. A male in the American ]\Iuseum of Natural 
History collected in Cuba, Soroa, Piiiar del Rio, June 2, 1955 
(A. F. Archer) . This specimen was with an immature M. forcipata 
(Thorell) , and a palpus from another male was found with females 
of M. forcipata (Thorell) taken in Cui)a, Siboney, Oriente, No- 
vember 17, 1945 (P. Olayo). 

'The term ■knee" is di-fimd u.s tlio place of articulation of the patella with the femur; 
it IS stiaiglit aii<l easily nuasured. The term and its usage have been liorrowed from 
Petrunkevitch's (1929, Trans. Connecticut .^cad. .-^rts Sci., 30:11) method of deriving the 
tiliial index. Tibial index is defined as width of patella X 100, divided by combmcd 
length of patella and tibia. 



256 



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MiCRATHENA cuBANA (Banks), 1909 
Figures 4-10 

Acrosoma cubana Banks, 1909. Juvenile holotype from San Diego de los 

Banos, Cuba, lost. 
Micraihena cubaiui, Bryant, 1940; Roevver, 1942; Bonnet, 1957. 

External Anatomy of Micrathena 
Figures 4-10, M. cubana 




Fig. 4. Posterior end of female. 

Figs. 5-7 Epigynum from below, in posterior view, and in profile, right 
side, respectively. 

Fig. 8. Palpal tarsal hook of male. 

Fig. 9. Paljjal tibia of male to show characteristic form. 

Fig. 10. Embolus and closely associated structures in male palpal tarsus, 
more enlarged. 



chickering: micrathena in the west indies 257 

Female. In addition to the abdominal spines described by Miss 
Bryant, there appear to be the remains of a reduced pair a short 
distance in front of the long, posterior j)air. The appearance of the 
two pairs of i)osterior spines is shown in Figure 4. I see the epigy- 
num as somewhat different from the figures accompanying Miss 
Bryant's desei'iption, and fur that reason have provided Figures 
5-7. 

Male. Total length of the male 5.07 mm. Small remains of the 
two pairs of posterior spines show fairly clearly. Palpus: the basal 
tarsal hook is curiously develoj^ed (Fig. 8) ; the tibia also has a 
characteristic form (Fig. 9) ; the embolus and related structures 
are also more or less distinctive (Fig. 10) . There is no ventral hook 
on the first coxa and, of course, the corresponding ridge and groove 
on the prolateral surface of the second femur are also lacking. 

Collection records. With the possible exception of one specimen 
from the Dominican Republic, all of the numerous specimens ex- 
amined are from Cuba; they are from many localities in this 
island. No males have been seen except those reported by Miss 
Bryant. 

MiCR.\THENA FORCiPATA (Thorell), 1859 
Figures 11-16 

Acmsoma forcipatum Thorell, 1859. Female holotype from Cuba, in the 

Natural History Museum, Stockholm. Butler, 1873; Petrunkeviteh, 1911; 

Bryant, 1940. 
Acmsoma flaromacidnla Keyserling, 1864. Female holotyi)e from Haiti, in 

the Briti.sh Museum (Nat. Hist.). Butler, 1873; Keyserling, 1892. 
Micrathena flavomaculata, Simon, 1895; Petrunkeviteh, 1911; Reimoser, 

1917; Roewer, 1942; Bonnet, 1957. 
Micrathena sexsjmiosa, Reimoser, 1917; Roewer, 1942; Bonnet, 1957. Not 

M.sexspiuosa (Hahn). 

During my visit to the British Museum (Natural History) in 
1958 I had the opportunity to study Keyserling's types of M. 
flavomaculata and to make drawings of the epigynum and the ab- 
domen. Since then I have been able to study several specimens of 
^[. forcipata (Thorell) and I have been forced to conclude thatiW. 
flavomaculata and forcipata are the same species. 

As Miss Bryant (1940) pointed out, Reimoser was clearly in 
error when he synonymized M. forcipata (Thorell) with M. sex- 
spinosa (Hahn). Roewer (1942) and Bonnet (1957) have both 
followed Reimoser. There are very clear and definite differences 
between these two species in both sexes and there should be no 
further confusion regarding their separation. 



258 



bulletin: museum of comparative zoology 



Female. Total length of Keyserling's type of M. flavomaculata 
from base of chelicerae to posterior end of al)domen in midline, 
8.97 mm; from base of chelicerae to opposite tips of large posterior 
spines, 11.5 mm. Corresponding measurements of a fairly typical 
specimen of M. forcipata (Thorell) from Cuba, 8.26 mm and 11.83 
mm. The four typical pairs of spines are well shown in Miss 
Bryant's figure 149 but important variations have been noted ; the 
anterior pair may be almost eliminated in certain specimens and 

External Anatomy of Micrathena 
Figures 11-16, M. forcipata 




Fig. 11. Dorsal view of abdomen, taken from type of M. flavomaculata 
(Keyserling). 

Figs. 12-13. Epigynum of type of M. flavomaculata (Keyserling) from 
behind, and in profile from right side, respectively. 

Figs. 14-15. Epigynum of typical M . forcipata from Cuba from below, and 
in profile from right side, respectively. 

Fig. 16. Palpal tunsal hook of male, nearly posterior \iew. 



nilCKKRIXC: MH'RATIIKXA IN THE WEST INDIES 259 

the typically claviform, long, posterior spines may show no distal 
swelling. The appearance of the epigynum (Figures 12-15) seems 
to be consistent. Cephalic part of carapace somewhat raised; 
median fovea a well-defined oval pit transversely situated; three 
pairs of dorsolateral foveae are developed in varying degrees in 
different specimens. Sternum with a well-defined, small, posterior 
tubercle. 

Male. There may still be some doubt about the correct match- 
ing of the sexes in this species, as concluded by Miss Bryant, but I 
think it highly probable that she was correct. Her figures 141 and 
146 show the male abdomen and palpus. The palpal tarsal hook is 
shown in Figure 16 in this paper. Contrary to Miss Bryant's state- 
ment concerning the absence of a ventral hook on the first coxa, I 
find a moderately well-developed hook together with the expected 
chitinized ridge and groove on the prolateral surface of the second 
femur near the proximal end. The male color pattern appears to be 
modified from that of the female. 

Collection records. Males are rare in collections; I have seen 
only the specimen described by Miss Bryant. Females have been 
taken in many localities in Cuba. I have seen a female from Car- 
refour, Haiti, collected by A. F. and M. H. Archer on July 22, 1955, 
and another female taken two miles east of Cayes du Jacmel, 
Haiti, Sept. 2, 1935, by W. G. Hasler. 

MiCRATHENA GENTILICIA Sp. nOV. 

Figures 17-22 

The specific name gentilicia is a Latin adjective meaning belong- 
ing to the group. 

Female holotype. Total length 4.55 mm to posterior end of 
lower posterior spines; total length to posterior end of abdomen 
between these spines 4.36 mm. Carapace 1.76 mm long; 1.17 mm 
wide just behind second coxae where it is widest; about 0.59 mm 
tall; the median fovea is a small, shallow pit; without dorsolateral 
foveae. 

Eyes. Viewed from above, anterior row strongly recurved, pos- 
terior row moderately so ; viewed from in front, anterior row nearly 
straight, posterior row strongly procurved, all measured from cen- 
ter. Median eyes on a moderately raised tubercle; lateral eyes like- 
wise. Central ocular quadrangle wider behind than in front in ratio 
of 14:9; wider behind than long in ratio of 14:11. Ratio of eyes 
AME:ALE:PME:PLE = 5:5:9:6 (lateral eyes very oval; long 



260 



bulletin: museum of comparative zoology 



diameters used for measurements) . AME separated from one an- 
other by about five-thirds of their diameter, from ALE by about 
four times their diameter. PINIE separated from one another by a 
little more than one and one-half times their diameter, from PLE 
by about nine-fourths of their diameter. Laterals separated from 
one another by the radius of ALE. Height of elypeus equal to 
eight-fifths of the diameter of AME. 

Chelicerae. Short, fairly robust ; quite gibbous in front in basal 
half; impossible to view teeth on margins of fang groove without 
damage to holotype ; a paratype has four teeth on promargin with 

External Anatomy of Micrathena 
Figures 17-22, M. gentilicia 




Figs. 17-19. Abdomen in dorsal, right lateral, and posterior views, re- 
spectively. 

Figs. 20-22. Epigynuui from below, in posterior view, and in profile, right 
side, respectively. 



CHIC'KKRIXC: MICRATIIEXA IN THE WEST INDIES 261 

tlio largest in tliiid place from base of fang, and three teeth on the 
reti'oniargin with all nearly uniform in size. 

SterniDn. Quite convex; latci'al tubercles not evident; not con- 
tinued between fourth coxae, which are separated by only about 
one-sixth of their width. 

Legs. 4123. Width of first patella at knee 0.17 mm, tibial 
index of first leg 12. AVidtli of fourth jiatella at knee 0.19 mm, tibial 
index of fourth leg 13. 

Femora Patollae Tibiae Metatarsi Tarsi Totals 

(All measurements in millimeters) 



I. 


1.36 


0.53 


0.86 


0.84 


0.53 


4.12 


II. 


1.28 


0.51 


0.75 


0.75 


0.53 


3.82 


III. 


0.90 


0.35 


0.52 


0.51 


0.44 


2.72 


IV. 


1.65 


0.48 


0.95 


0.99 


0.55 


4.62 



Legs with fev/ spines but with many setigerous tubercles. Nu- 
merous trichobothria on tibiae, metatarsi, and tarsi. 

Abdomen. General form with spination shown in Figures 17-19. 
There is no evidence of additional small spines on available para- 
types. 

Epigymnn. Rather complicated; the pattern has not been seen 
in other species (Figs. 20-22). 

Color in alcohol. Carapace brownish, darker through median 
region ; much darker along ventrolateral margins. Sternum yellow- 
ish with black flecks and irregular black spots. Legs brownish with 
variations. Abdomen with a complicated color pattern: there is an 
oval, central, dorsal, white spot (stippled in Fig. 17) ; the lateral 
sides of the anterior spines and adjacent lateral abdominal walls 
are whitish; additional pairs of white spots on the dorsum and 
lateral sides are irregular, somewhat indefinite and difficult to de- 
scribe adequately, and probably highly variable; the venter is 
nearly black through the broad center, with white on each side. 

Type locality. The holotype and three paratype females were 
collected in Trinidad. W. L, between 1934 and 1936, by N. A. 
Weber but no further data are given on the labels. The male is not 
known. 

MiCRATHENA GERTSCHI Sp. nOV. 

Figures 23-29 

Male holotype. Total length about 4.55 mm (body somewhat 
distorted) . Carapace 1.78 mm long; 1.20 mm wide opposite interval 
between second and third coxae where it is widest; with the usual 



262 bulletin: museum of comparative zoology 

nearly circular central fovea; somevv^hat overlapped by anterior 
border of abdomen ; essentially typical of males of the genus. 

Eyes. Lateral tubercles moderately well developed; A]\IE lo- 
cated on a well-developed tubercle considerably extended forward 
over the clypeus. Viewed from above, both rows strongly recurved ; 
viewed from in front, anterior row gently recurved, posterior row 
gently procurved; all measured from center. Central ocular quad- 
rangle wider behind than in front in ratio of 20:17; nearly as long 
as wide behind. Ratio of eyes AME: ALE: PME:PLE =-6:5:7:4.5 
(laterals irregular in outline). AME separated from one another 
by about L5 times their diameter, from ALE by about ten-thirds 
of their diameter. PME separated from one another by about nine- 
sevenths of their diameter, from PLE by about three times their 
diameter. Laterals separated from one another by about one-third 
of the diameter of PLE. Clypeus strongly receding; height equal to 
about twice the diameter of AME. 

Chelicerae, Maxillae, and Lip. Difficult to examine without in- 
jury to the holotype; apparently typical of males of the genus. 

Sternum. Oval in general outline ; extended between all coxae ; 
fourth coxae separated by two-thirds of their width; with nu- 
merous stiff, black bristles. 

Legs. 1423. Width of first patella at knee 0.16 mm, tibial in- 
dex of first leg 11. Width of fourth patella at knee 0.14 mm, tibial 
index of fourth leg 12. 

Femora Patellae Tibiae Metatarsi Tarsi Totals 

(All measurements in millimeters) 
I. 
II. 
III. 
IV. 
Palpus 

The characteristic ventral spines on the first and second tibiae 
are shown in Figures 24 and 26. Spines on the first femur as seen in 
prolateral view are shown in Figure 25. The ventral hook on the 
first coxa is small and pointed; the corresponding prolateral, chiti- 
nized ridge and groove on the second femur are moderately well 
developed near its proximal end. Trichobothria occur on the tibiae 
but not elsewhere. 

Palpus. Figures 27-29. The basal tarsal hook appears to be dis- 
tinctive. The tibia is conservative. 

Abdomen. Figure 23; only slightly flattened dorsoventrally ; 
the spinnerets are located only a little behind the middle of the 
venter and are surrounded by a ]ioorly chitinized ring. 



1.54 


0.44 


1.06 


0.91 


0.42 


4.37 


1.39 


0.40 


0.81 


0.70 


0.41 


371 


0.77 


0.29 


0.35 


0.44 


0.31 


2.16 


1.54 


0.35 


0.81 


0.88 


0.42 


4.00 


0.31 


0.13 


0.15 




0.55 


1.14 



chickering: micrathena in the west ixdies 



263 



External Anatomy of Micrathena 
Figures 23-29, M. gerlnchi 




Fig. 23. Body of male, dor.sal view. 

Fig. 24. Right first tibia, ventral view. 

Fig. 25. Right first femur, prolateral view. 

Fig. 26. Right second tibia, nearly ventral view. 

Fig. 27. Left palpal tarsus. 

Fig. 28. Left basal palpal tarsal hook and base of 

Fig. 29. Tlip same from nearly jio.sterior view. 



•vmbium. 



Color in alcoJiol. Legs yellowish with variations. Mouth parts 
brownish. Palpi like legs except that cymbium is very dark brown. 
Carapace medium brown with fine, dark, irreguhir dots; a lighter 
area extends from the median fovea to the posterior border. The 



264 bulletin: museum of comparative zoology 

sternum is brown with darker streaks. Abdomen: the dorsum is 
brown with a nearly white spot in the middle and a light streak ex- 
tending through the middle from the white spot to the anterior 
border; the sides are yellowish with many irregular, whitish flecks; 
the venter has a brownish median stripe with many small, yellow- 
ish flecks. 

Type locality. The holotype male is from Simla, Trinidad, 
W. I., December 12, 1954 (A. M. Nadler). 

Other records. One paratype male is also from Simla, February 
26, 1959 (A. M. Nadler) , and another is from Diego-Martin, Trini- 
dad, W. I., Sept. 8, 1946 (R. H. Montgomery). The female is un- 
known. 

MiCRATHENA LEPIDA Sp. UOV. 

Figures 30-34 

Several females of a single species have recently been found in 
a collection in the Museum of Compartive Zoology, all taken on 
the Island of Trinidad, W. I., by R. Thaxter and Dr. P. J. Darling- 
ton, Jr. The males described in this paper as M. nitida were found 
with some of these females and there is a suspicion that they 
belong together. However, as several other kinds of females were 
also present in the collection, it seems undesirable to unite AI. 
lepida and nitida until there are more data regarding their rela- 
tionship. One of the females has been selected as the holotype of 
M. lepida. This species appears to belong in the group including 
M. sagittata (Walckenaer) and M. gladiola ( Walckenaer) . The 
name lepida is a Latin adjective meaning pleasant. 

Female holotype. Total length to posterior border of abdomen 
5.56 mm; to tips of posterior spines 6.05 mm. Carapace consider- 
ably overlapped by anterior end of abdomen; about 2.28 mm long; 
about 1.95 mm wide opposite second coxae where it is widest; 
median fovea hardly visible as a shallow depression ; without dor- 
solateral foveae; of moderate height; without gibbosity posterior 
to median fovea ; ocular tubercles only moderately developed. 

Eyes. Posterior row slightly longer than anterior row. Viewed 
from above, anterior row strongly recurved, posterior row only 
moderately so. Viewed from in front, anterior row nearly straight, 
posterior row moderately procurved, all measured from center. 
Ratioofeyes AME:ALE:PME:PLE = 10:8.5:12:8.5. AME sep- 
arated from one another by their diameter, from ALE by nearly 
four times their diameter. PME separated from one another by 
slightly more than 1.5 times their diameter, from PLE by nearly 



CHICKERINCi: MI(HAIlli:XA IX TIIK WEST INDIES 



265 



External Aualoiny of M icralhena 
Figures 30-34, M . lepida 




30 



32 



Fig. 30. Body of female, dorsal view. 
Fig. 31. Posterior end of abdomen of female. 

Figs. 32-34. Epigymim from holow, in posterior view, and in iirofilo, riglit 
side, respectively. 



three times their diameter. LE separated from one another by a 
Httle less than their ra(hiis. Central ocular quadrangle wider be- 
hind than in front in ratio of about 10:7; wider behind than long 
in ratio of about 4:3. Height of clypeus equal to slightly more than 
the diameter of AME. 

Chelicerae. Moderately robust, parallel, with basal boss well 
developed as a chitinous ridge; fang groove with four teeth along 
promargin and three along retromargin. 



266 bulletin: museum of comparative zoology 

Lij). Wider than long in ratio of about 11:6, reaching some- 
what beyond middle of maxillae. 

Sternum. Scutiform as usual; moderately convex but not 
raised into a cone as in M. gladiola (Walckenaer) ; lateral tuber- 
cles only moderately developed; not extended between fourth 
coxae, which are separated by slightly more than one-half of their 
width ; sternal suture gently procurved. 

Legs. 4123. Width of first patella at knee 0.22 mm, tibial in- 
dex of first leg 11. Width of fourth patella at knee 0.24 mm, tibial 
index of fourth leg 13. 

Femora Patellae Tibiae Metatarsi Tarsi Totals 

(All measurements in millimeters) 



I. 


2.02 


0.72 


1.30 


1.20 


0.65 


5.89 


II. 


1.95 


0.65 


1.11 


1.11 


0.59 


5.41 


III. 


1.37 


0.46 


0.73 


0.72 


0.55 


3.83 


IV. 


2.47 


0.65 


1.25 


1.43 


0.72 


6.52 



Legs with few spines but with many setigerous tubercles ; espe- 
cially true of femora. 

Abdomen. Closely resembling that of M. gladiola (Walcken- 
aer), but distinct (Fig. 30). There are three pairs of spines, but 
no indications of the small posterior spines that occur on both M. 
sagittata and M. gladiola. 

Eyigynum. Figures 32-34. Variation of this organ may be 
caused by injuries incurred in handling. 

Color in alcohol. Carapace reddish brown with irregular lighter 
and darker streaks. Legs light reddish brown, lighter beneath. Ab- 
domen yellowish white dorsally with usual "punctures"; spines 
reddish ; sides with alternating, narrow, black and yellowish-white 
stripes bordering the longitudinal grooves; posterior surface es- 
sentially the same. Color pattern probably variable in a large 
po]:)ulation. 

Type locality. The holotype female is from Port-of-Spain, 
Trinidad, W. L, April 1913 (R. Thaxter). 

Other records. Six paratype females were collected with the 
holotype from Mt. Tucuche, Trinidad, April 1929 (P. J. Darling- 
ton, Jr.). A female in the British Museum (Natural History) 
thought to belong to this species, was collected by Capt. A. K. 
Totten of LLAI.S Rodney, January 2, 1931, in Maracas Valley, 
Moran Pool. Trinidad. The male is not known. 



CHICKEKI.\'(;: MICRATHKNA IN THE WKST INDIES 267 

MiCRATHENA LEVII sp. nOV. 

Figures 35-40 

Male holotype. Total length 3.8 mm. Carapace 1.69 mm long; 
1.41 mm wide opposite interval between second and third coxae 
where it is widest; much narrowed at posterior border; smoothly 
rounded along margins and dorsum ; median fovea hardly discerni- 
ble; not overlapped by anterior border of abdomen. 

Eyes. Lateral ocular tubercles moderately well developed ; cen- 
tral ocular tubercle also moderately well developed with AME ex- 
tended forward to make clypeus very receding. Viewed from 
above, both rows rather strongly recurved; viewed from in front, 
anterior row gently recurved, posterior row definitely procurved, 
all measured from center. Central ocular quadrangle wider behind 
than in front in ratio of nearly 3:2; wider behind than long in ratio 
of about 27 : 22. Ratio of eyes AME: ALE: PME:PLE = 6.5:6:8:5. 
AME separated from one another by nearly their diameter, from 
ALE by about three times their diameter, from PLE by nearly 2.5 
times their diameter. Laterals separated from one another by 
about one-third of the diameter of PLE. Height of clypeus equal 
to about 2.7 times the diameter of AME. 

Sternum. Only slightly convex; finely rugulose; with the usual 
sparse covering of stiff bristles; scutiform in general but continued 
between all coxae; fourth coxae separated by about two-fifths of 
their width. 

Legs. 4123. Width of first patella at knee 0.15 mm, tibial in- 
dex of first leg 14. Width of fourth patella at knee 0.12 mm, tibial 
index of fourth leg 12. 





Femora 


Patellae 


Tibiae 


Metatarsi 


Tarsi 


Total 






(All measurements in 


millimeters) 






I. 


1.19 


0.40 


0.68 


0.66 


0.44 


3.37 


II. 


1.17 


0.37 


0.62 


0.59 


0.40 


3.15 


III. 


0.73 


0.29 


0.46 


0.40 


0.33 


2.21 


IV. 


1.32 


0.33 


0.68 


0.73 


0.42 


3.48 



Palpus 0.27 0.13 0.14 0.62 1.16 

The length of the palpal tarsus as given in the above tai)le in- 
cludes the extended basal hook. There is no ventral hook on the 
first coxa and no chitinized, prolateral ridge and groove on the 
second femur as so often occurs in this genus. The ventral spines on 
the first and second tibiae are shown in Figures 36-37. Tricho- 
bothria on the dorsal surfaces of the tibiae are apparently arranged 
in two rows. 



268 



bulletin: museum of comparative zoology 



External Anatomy of Micrathena 
Figures 35-40, M. levii 




35 




38 



Fig. 35. Body of male, dorsal view. 

Fig. 36. Left first tibia, ventral view. 

Fig. 37. Left second tibia, ventral view. 

Fig. 38. Left palpal tarsus. 

Figs. 39-40. Two different views of palpal basal tarsal hook. 



PalpuH. Fip;ures 38-40. I have not seen this type of basal tarsal 
hook in any other species. Both tibia and patella are short with 
the tibia relatively very broad and somewhat trilobed. 

Abdomen. Figure 35. Moderately flattened dorsoventrally with 
no distinct indication of suppressed spines. 

Color in alcohol. Legs medium brown with variations. Cara- 
pace medium brown with fine, irregular, dark dots. Sternum 
brownish with irregular, white, deposits. Abdomen dorsum yellow- 
ish with irregulai'ly jilaccd, white spots; as indicated in Figure 35 
there is a series of irregular grayish spots also on the dorsum; 
the venter in front of genital groove and the sclerotized ring 
around the spinnerets are brown, but behind the genital gi'oove 
the color is y(>llowish with irregular gray lines and spots. 

Type locality. Male holotype is from Simla, Trinidad. W.T.. 
February 26, 1959 (A. M. Nadler). The female is unknown. 



CIIICKKKIXC: MICKATHKNA IN THE WEST INDIES 269 

MiCRATHENA MiLiTARis (Fabi'icius), 1775 
Figures 41-50 

Amnea militaris Fabricius, 1775. Tlolotyiio from Amoricn. Probably in llin 

Copenhagpn Natural History Museum. 
Pleclana viilitari.s. Walokonaor, 1841. 
Micrathena jnUllaris, Pctrunkcvitch, 1911; Reimoser, 1917; Pelrunkevitcli, 

1926, 1930; Bryant, 1940; Roewor, 1942; Bryant, 1945; Bonnet, 1957. 
Micrathenn armata, Bryant, 1940, 1945 [not Aranea armata Olivier]. 

Much confusion has existed concerning the status of what is 
generally regarded as M. inilitarif>. The species has often been 
filed in collections as M. sagittata and M. forcipata (Thorell), 
frequently as M. militaris. Miss Bryant regarded M. armata 
(Olivier) as a synonym of M. militaris, and her conclusion has 
generally been followed. Dr. Petrunkevitch (1926) may have had 
the species from the Virgin Islands but his figure of the epigynum 
does not agree with the specimens I have studied from Cuba, 
Haiti, and the Dominican Republic. I am not able to clarify the 
confusion but I can point out certain inconsistencies. I have noted 
in the epigyna significant differences between typical females from 
Cuba and specimens from Haiti and the Dominican Republic. 
These differences may be observed by a comparison of Figures 
42-44 with Figures 45-47. Miss Bryant (1940) described what she 
regarded as the male of the species; some have doubted the 
validity of her identification, but, after examination of several 
males from Haiti, the Dominican Republic, and Puerto Rico, 
taken with females from these same regions, I am ready to accept 
her conclusion until we have definite evidence to the contrary. I 
have been unable to find males from Cuba that can be definitely 
associated with females from that i.'^land, and this again empha- 
sizes the need for intensive field work in the whole West Indian 
region. 

Females. Total length of a specimen from Cuba is 7.61 mm 
from Aj\IE to posterior border of abdomen between the large 
posterior spines; total length from anterior border of somewhat 
gibbous bases of chelicerae to the tips of the posterior spines 
11.83 mm. Considerable variation in size of mature females has 
been noted. The two pairs of spines shown in Figure 41 and in 
Petrunkevitch's figure (1926) are those to which reference is 
usually made. Frequently, however, a pair of very small dorso- 
lateral spines occurs about half way between the bases of the 
long, posterior spines and the much i^maller, very erect antero- 
dorsal spines. Less frequently another very small spine occurs at 
about the base of each of the large posterior spines and is directed 



270 



bulletin: museum of comparative zoology 



posteriorly. The promargin of the fang groove on a fairly typical 
female from Haiti bears five teeth, three of which are relatively 
small and placed somewhat irregularly; the retromargin bears 
three teeth of moderate size, regularly placed. The Cuban speci- 
men chosen to show the features of the epigynum has four teeth 
on the promargin and three on the retromargin. Females fre- 
quently have an embolus and accompanying sheath caught in 
one receptacle, and, occasionally, an embolus in each receptacle, 
an occurrence first reported for this species by Petrunkevitch in 
his study of the species in Puerto Rico. The sternum is rugulose; 
it has three pairs of prominent tubercles and terminates in a 
prominent, median, extended, conical tul)ercle. The most puzzling 
variations of all concern the epigynum: Figures 42-44 show its 
appearance in a female selected from many specimens collected 
in the Dominican Republic, viewed in three different positions; 
Figures 45-47 show its appearance in a female collected in Havana, 
Cuba. My brief study of numerous specimens from several islands 
in the West Indies certainly suggests the possibility that what 
is now regarded as one species may, upon further study, be 
divided into two or more. 



External Anatomj' of Micrathena 
Figures 41-44, M. militaris 



43 




42 



Fig. 41. Abdomen viewed from posterior end. 

Figs. 42-44. Epigynum from below, in posterior view, and in iirofilo from 
right side, respectively (Fig. 44 more enlarged). 



chickering: micrathexa in the west indies 



271 



External Anatomy of Micratheua 
Figures 45-50, 3/. militnris 




Figs. 45-47. Ei)igynum from below, in posterior view, and in jirofile from 
right side, respectively (specimen from Cuba) . 
Fig. 48. Dorsal view of abdomen of male. 
Fig. 49. Left palpal tibia. 
Fig. 50. Left palpal basal tarsal hook. 



Male. Total length 3.95 mm. The sternum is irregularly rugu- 
lose; the tubercles, so prominent in the female, are present but 
much less developed. The teeth along the fang groove differ from 
those of the female ; the promargin appears to bear four teeth ; the 
retromargin has four teeth with the distal two set very close 
together. Figure 48 shows the form of the abdomen as viewed 
from above. Figures 49-50 show the important features of the 
palpal tibia and basal tarsal hook. There is no ventral hook on 



272 bulletin: museum of comparative zoology 

the first coxa and no corresponding chitinized ridge and groove 
on the second femur. 

Collection records. The male described here and the female 
from which Figures 42-44 were taken, were collected at Jarabacoa, 
La Vega, Dominican Republic, May 11, 1959, by Drs. M. W. 
Sanderson and T. H. Farr. The female from which Figures 45-47 
were taken was collected in Havana, Cuba, with no date indi- 
cated, and was originally identified as M. armata (Olivier). Nu- 
merous specimens have been studied from Cuba, Puerto Rico, 
Haiti, and the Dominican Republic. 

MiCRATHENA NITIDA Sp. nOV. 

Figures 51-56 

The males described below were, for a time, regarded as M. 
macilenta Chickering, described from Panama, but after a more 
careful study and direct comparison it now seems quite certain 
that we are dealing with a new, closely related species. 

The name nitida is a Latin adjective meaning elegant. 

Male holotype. Total length 4.03 mm. Carapace 1.6 mm long, 
1.3 mm wide opposite interval between second and third coxae 
where it is widest; with eyes on moderately well-developed 
tubercles; the moderately well-developed median fovea is nearly a 
round pit; with no dorsolateral foveae; nearly flat along the mid- 
dle from PME to posterior declivity; very finely granulated. 

Eyes. Posterior row only slightly wider than anterior row. 
Viewed from above, both row^s strongly recurved. Viewed from 
in front, anterior row nearly straight, posterior row moderately 
procurved, all measured from center. Ratio of eyes AME:ALE: 
PME:PLE = 5.5:5:7.5:5. AME separated from one another by 
slightly more than their diameter, from ALE by slightly less than 
three times their diameter. PME separated from one another by 
five-sevenths of their diameter, from PLE by about twice their 
diameter. LE separated from one another only by a broad line. 
Central ocular quadrangle wider behind than in front in ratio of 
about 6:5; about as long as wide behind. Clypeus very receding; 
height of clypeus equal to about twice the diameter of AME. 

Sternum. Generally oval in outline with the usual scalloped 
margin; extended between fourth coxae, which are separated by 
about three-fourths of their width. 

Legs. 1423. Width of first patella at knee 0.13 mm, tibial 
index of first leg 11. Width of fourth patella at knee 0.11 mm, 
tibial index of fourth leg 11. 



chickkrixg: mkkathexa in the west indies 



273 



External Anatomy of Micmlhota 
Figures 51-56, M. nilida 




Fig. 51. Body of male, dorsal view. 

Figs. 52, 54. Left first and second tibia, respectively, ventral view. 

Fig. 53. Left first femur, ventral view. 

Fig. 55. Left palpal tibia and tarsus. 

Fig. 56. Pali)al basal tarsal hook, nearly posterior view. 



I. 


1.25 


II. 


1.10 


III. 


0.73 


IV. 


1.32 


Palpus 


0.26 



Femora Patellae Tibiae Metatarsi Tarsi Totals 

(All measurements in millimeters) 

0.39 0.81 0.70 0.40 3.55 

0.37 0.60 0.55 0.35 2.97 

0.29 0.37 0.37 0.29 2.05 

0.33 0.65 0.70 0.39 3.39 

0.12 0.14 0.48 1.00 

First leg with many long robust spines on femur and tibia 
(Figs. 52-53) ; second leg with short robust spines on tibia (Fig. 
54) ; first coxa with a ventral hook and second femur with the 
corresponding prolateral ridge and groove, all moderately well 
developed; fourth leg with long spines on femur, patella, and 
tibia, but less developed than on first and second legs; ii few- 
other spines also present. Two trichobothria observed on the. 
dorsal side of all tibiae. v .■••.•. 



274 bulletin: museum of comparative zoology 

Palpus. Details rather closely resemble those of palpi of sev- 
eral other species, but there are specific differences somewhat 
difficult to represent adequately in drawings (Figs. 55-56) . 

Abdomen. Much flattened in the manner common among 
males in this genus; with general form as shown in Figure 51; 
with obscure indications of suppressed spines at posterior end. 

Color in alcohol. Legs and mouth parts with varying shades 
of light brown and yellowish brown. Carapace medium brown 
with black flecks except for a light stripe extending posteriorly 
from the median fovea. Abdomen: dorsum yellowish with a nar- 
row dark marginal stripe on each side; venter yellowish with a 
narrow dark lateral stripe. 

Tijpe localitij. The holotype male is from Trinidad, W.I., near 
Port-of-Spain, April, 1913 (R. Thaxter). Several paratype males 
are in the collection from Trinidad; one is from Sangre Grande, 
April, 1913 (R. Thaxter) ; another is from Port-of-Spain, Febru- 
ary, 1926 (W. S. Brooks) ; the remainder are from the same lo- 
cality as the holotype and, apparently, taken at about the same 
time. 

MiCRATHENA PRAETERITA sp. nOV. 

Figures 57-63 

The holotype described here together with numerous paratypes 
came to me identified as M. bicolor (Keyserling) . There are super- 
ficial resemblances, but the details of structure indicate clearly 
that these specimens do not belong with Keyserling's species. Dur- 
ing my period of work in the British Museum (Natural History) 
in 1958 I was able to study Keyserling's types of M. bicolor. This 
acquaintance has helped me to determine that the species has 
never been described. The specific name praeterita is a Latin 
adjective meaning not noticed. 

Female holotype. Total length, including the slightly extended 
bases of the chelicerae 4.75 mm. Carapace 1.7 mm long; 1.01 mm 
wide opposite posterior border of second coxae where it is widest; 
with indistinct median fovea a short, shallow groove; with no 
special features; without dorsolateral foveae; cephalothoracic 
groove very indistinct. 

Chelicerae. Moderately well developed ; without special modi- 
fications; typical of females of the genus; fang groove well de- 
fined; in a paratype the promargin of the fang groove has three 
teeth, the middle one of which is considerably the largest; the 
retromargin also has three teeth in this paratype, with the one 
nearest the base of the fang somewhat the largest. 



chickering: micrathena in the west indies 



275 



External Antiloiny of Micralheiia 
Figures 57-63, M . praeterila 




57 



Fig. 57. Body of female, dorsal view. 
Fig. 58. Posterior end of abdomen. 
Fig. 59. Lateral view of right anterior abdominal spine. 
Figs. 60-62. Epigynum of holotype from below, in posterior view, and in 
profile from right side, respectively. 
Fig. 63. Appearance of epigynum after lo.ss of thin, jirojecting shelf. 



Maxillae. Short, broad, parallel; also typical of females of the 
genus. 

Lip. Wider than long in ratio of about 9:5; does not quite 
reach to middle of maxillae. 



I. 


1.38 


II. 


1.28 


III. 


0.92 


IV. 


1.65 



0.54 


4.12 


0.53 


3.81 


0.35 


2.59 


0.62 


4.72 



276 bulletin: museum of comparative zoology 

Sternum. Scutiform in general; sternal suture strongly pro- 
curved; moderately convex; not continued between coxae; ter- 
minates in a point at beginning of space between fourth coxae, 
which are separated by nearly one-fourth of their width. 

Legs. 4123. Width of first patella at knee 0.21 mm, tibial 
index of first leg 15. Width of fourth i)atella at knee 0.21 mm, 
tibial index of fourth leg 14. 

Femora Patellae Tibiae Metatarsi Tarsi Totals 

(All measurements in millimeters) 

0.53 0.86 0.81 

0.48 0.77 0.75 

0.35 0.53 0.44 

0.51 0.95 0.99 

The palpal claw is finely pectinated. Spines are nearly absent 
from the legs; setigerous tubercles are moderately well developed. 
Trichobothria have been clearly observed only on the tibiae. 

Abdomen. Figures 57-59. The three pairs of spines resemble 
those of some other .species, but there are ahso di.stinctive features 
among these. Additional spines, frequently found in certain other 
species, are either rare or lacking altogether in this species. 

Epigynimi. Figures 60-62 illustrate the holotype. Note that 
the thin shelf extending ventrally from beneath the ventral border 
is frequently lacking in paratype, presumably because of break- 
age. In paratypes that have lost this part the superficial appear- 
ance of the organ is quite different. Figure 63 is intended to show 
the appearance of the epigynum in posterior view on an individual 
that has lost the shelf and probably was also under greater in- 
ternal pressure than was the holotype. 

Color in alcohol. The legs are medium brown with variations. 
Mouth parts are much the same. The carapace is brown with 
radiating darker streaks and a darker median .stripe leading from 
PME nearly to the median fovea. All of these marks are i)oorly 
defined. The sternum is brownish with dark streaks and spots 
throughout. Abdomen with a w^hite, black and brown color pat- 
tern difficult to describe adequately; the dorsum has an elongated 
white spot along the posterolateral side of each of the anterior 
spines ; a narrow, irregular, brown stripe extends along the median 
side and dorsal surface of each of the anterior spines and reaches 
back nearly to the middle of the dorsum; an irregular white stripe 
extends between the two anterior spines and along the middorsal 
surface to nearly opposite the bases of the large posterior spines; 
lateral to these marks there is a mixture of white and brown 



chickerixg: micratiiena in the west ixdies 277 

patches; between the bases of the hirj^e posterior spines there is a 
transverse row of five white patches; tlie venter has a broad, black 
stripe extending from the genital groove and dividing to extend 
dorsally for a considerable distance as a pair of black stripes 
directed toward the small posterior spines. Considerable variation 
in the color pattern has been noted among the paratypes as would 
be expected. For example, the ii'regular white stripe in the dorsum 
of the holotype may be broken into white spots by encroachment 
of the brown color that laterally bounds the white: the brown 
color may be reduced with an increase in the wliite until the latter 
predominates. 

Type locality. The female holotype is from St. Augustine, 
Trinidad, W.I., September 18, 1946 (R. H. Montgomery). Nine- 
teen paratype females were, apparently, collected with the holo- 
type. The male is unknown. 

MiCRATHENA RUFOPUNCTATA (Butler) , 1873 

Figures 64-67 

Acrosoma rufopunctatum Butler, 1873. Holotype from Janiaica, sex not 

indicated, in British Museum (Nat. Hist.). 
Micrathena rufopiDictata Petrunkovitch, 1911; Reimoser, 1917; Roewer, 

1942; Bonnet, 1957. 

The author of this species gave a very inadequate description 
unaccompanied by figures. Reimoser (1917) merely repeated the 
original description. There has never been any detailed description 
published. 

Female. Total length 5.85 mm, including the bases of the 
somewhat convex chelicerae and relatively long posterior abdom- 
inal spines. Carapace: largely overlapped by extended dorsal 
portion of abdomen and anterior spines; median thoracic fovea a 
small, rounded pit; with a series of faintly indicated dorsolateral 
foveae. 

Eyes. Viewed from above, anterior row moderately recurved, 
posterior row slightly so. Viewed from in front, anterior row 
slightly recurved, posterior row moderately jirocurved, all meas- 
ured from center. Central ocular quadrangle wider behind than in 
front in ratio of 25 : 21 ; wider behind than long in ratio of 
25 : 23. Ratio of eyes AME : ALE : Pi\IE : PLE = 7.5 : 6.5 : 
8.5 : 6. AME separated from one another by slightly less than 
their diameter, from ALE by about four times their diameter. 
PME separated from one another by nearly seven-sixths of 
their diameter, from PLE by slightly more than three times 



278 



bulletin: museum of comparative zoology 



their diameter. Laterals separated from one another by about 
one-third of the diameter of PLE. Height of clypeus about equal 
to the diameter of AME. 

Sternum. A simple scutiform; sternal suture slightly pro- 
curved; with anterolateral tubercles moderately developed; with 
a minute tubercle opposite each coxae 1-3 and another minute 
tubercle at blunt posterior end, which is not extended between 
fourth coxae; fourth coxae separated by about one-third of their 
width. 

Legs. 4123. Width of first patella at knee 0.25 mm, tibial 
index of first leg 15. Width of fourth patella at knee 0.21 mm, 
tibial index of fourth leg 14. 

External Anatomy of Micrathena 
Figures 64-67, M . rujopunciata 




Fig. 64. Body of female, dorsal view. 

Figs. 65-67. Epigynum from below, in posterior view, and in profile from 
right side, respectively. 



Femora 



I. 


1.54 


II. 


1.45 


III. 


0.97 


IV. 


1.76 



Patellae Tibiae Metatarsi 

(All measurements in millimeters) 
0.62 1.01 1.08 

0.57 0.88 0.95 

0.40 0.53 0.55 

0.55 0.92 1.10 



Tarsi 



Totals 



0.53 


4.78 


0.53 


4.38 


0.44 


2.89 


0.48 


4.81 



chickering: micratiiena in tiiio west indies 279 

Legs with numerous short, slender spines and many setigerous 
tubercles. Triehohothria observed on tibiae; doubtful elsewhere. 
Palpal claw finely toothed. 

Abdomen. General form as viewed from above shown in Figure 
64. There are only two pairs of spines and no indication of small 
accessory spines such as often appear in the genus. The anterior 
border and spines are extended far over the carapace. 

Epigynum. In essential features, shown in Figures G5-67, 
e])igynum closely resembles that of M. mitrata (Hentz), M. 
cubana (Banks), M. mnrfnrlanei Chickering, M. fidelis (Banks) 
and probably others. 

Color in alcohol. The color pattern on the abdomen is distinc- 
tive. The carapace, mouth parts, and legs are all rich reddish 
brown with variations. The sternum is dark brown. Abdomen: 
The dorsolateral sides are bright yellow; this marginal stripe in- 
cludes the anterolateral spines but stops at the bases of the 
posterolateral spines; there is also a yellow marginal stripe ex- 
tending along the posterior border between the two posterolateral 
spines; the latter spines themselves are rich reddish brown; the 
remaining dorsal region is grayish, darker around the border, and 
almost white in the center; the lateral and ventral areas are pre- 
dominantly very dark brown, almost black; the venter has three 
pairs of bright yellow spots introduced into the brown back- 
ground; the most anterior pair of these yellow spots is at the 
level of the epigynum ; the second pair at about the level of the 
spinnerets ; the third pair is near the posterior border. I have seen 
no color pattern like this among the many species in the genus 
studied during the past several years. 

Collection records. The original specimens were reported from 
Jamaica, W.I., in 1873. So far as I have been able to determine, 
the species has not been reported from that time until the present. 
Three females in the American Museum of Natural History were 
taken by Dr. T. H. Farr, Institute of Jamaica, Kingston, Jamaica, 
W.I., at the entrance to Mt. Diablo Forest Reserve, June 29, 1960. 
The male remains unknown. 

MiCRATHENA siMiLis Bryant, 1945 
Figures 68-71 

Micrathena siviilis Bryant, 1945. Female holotype from Dominican Rppuh- 
lic, Piierta Plata, 30 August, 1938, in the Museum of Comparative Zoology. 
This species has been under close scrutiny for some time and its 



280 



bulletin: museum of comparative zoology 



validity as a distinct species is still uncertain. Miss Bryant con- 
sidered it closely related to M. cubana (Banks). It should be re- 
studied when a large series is available. Three specimens are 
known to me: the holotype, a paratype female from the Domini- 
can Republic, Mt. Diego de Ocampo, North Range, 3000-4000 ft. 
el., July, 1938 (P. J. Darlington, Jr.) ; one female from Dominican 
Republic, Valle de Polo, Prov. de Barahona, August 18, 1935 
(W. G. Hasler). The male remains unknown. The epigynum ap- 
l)ears quite different than represented by Miss Bryant's figures 
8 and 43 (1945). 



External Anatomy of Micrathena 
Figures 68-71, M. similis 




70 





Fig. 68. Posterior end of abdomen from behind. 

Figs. 69-71. Epigynum from below, in posterior view, and in profile from 
right side, respectively. 



BIBLIOGRAPHY 

Banks, N. 

1909. Arachnida of Cuba. Sec. Rept. Centr. Exper. Stat. Cuba, pj). 
150-174, 45 pis. 

BONNKT, P. 

1957. Bibli(^f;raphia Araneorum. Toulouse. Vol. 2 (3). 



CIIICKKRIXC. : MICRATIIKXA I X THE WEST INDIES 281 

Bryant, Elizabeth 

1940. Cuban s])iders in I he Musouni of Comparative Zoology. Bull. 

Mus. Comp. Zool.. 86(7) : 249-532, 22 pis. 
1945. The Argioi)ida(> of Hispaniola. Bull. Mus. Conip. Zool., 95(4) : 

359^18,4 pis. 

BlITLEK, A. G. 

1873. A list of spitlcns of Ur- gtaius Acrosomd, wi(h descriijlions of new 

species. Proc. Zool. Soc. London, pp. 420-429. 
Chickering, a. M. 

1960a. Three new species of Micmlhcua (Arancac, ArKio])idac) from 

South America. Breviora, Mus. Comp. Zool., No. 121: 1-11. 
19601j. Notes on certain sjoecies of Micrathena (Araneae, Argiopidae) 

from South America. Breviora, Mus. Comp. Zool., No. 122: 1-7. 
1960c. Six now species of Micrathena (Araneae, Argiopidae) from South 

America with notes on known species. Proc. Zool. Soc. London, 

pp. 65-89, 90 figs. 
1961. The genus Micrathena (Araneae, Argiopidae) in Central America. 

Bull. Mus. Comp. Zool., 125(13) : 380-470. 
Fabricius, J. C. 

1775. Systema Entomologiae. Vol. II, pp. 434. 
Keyserling, Graf E. von 

1864. Beschreibung neuer und wenig bekannter Arten aus der Familie 

Orbitelae. Sitzber. naturwiss. Gesell. Isis, Dresden, 1863: 63-98, 

119-154, pis. 1-7. 
1892. Die spinnen Amerikas. 4. Epeiridae. Nurnberg. Baur & Raspe. 
Petrunkevitch, A. 

1911. A synonymic index-catalogue of spiders of North, Central, and 

South America. Bull. Amer. Mus. Nat. Hist., 29: 1-809. 
1926. Spiders from the Virgin Islands. Trans. Connecticut Acad. Arts 

Sci., 28: 21-78, 28 figs. 
1930. The spiders of Porto Rico. Pt. 2. Trans. Connecticut Acad. Arts 

Sci., 30: 159-355, 240 figs. 
Reimoser, E. 

1917. Die Spinnengattung Micrathena Sundevall. Verli. zool. bot. 

Gesell. Wien, 67(%) : 73-160. 

ROEWER, C. Fr. 

1942. Katalog der Araneae. Vol. 1; 1-1040. 
Simon, E. 

1892- Histoire naturelle des Araignees. Deuxieme Edition. 2 Vols. 

1903. Librarie Encyclopedicjue de Roret, Paris. 
Sundevall, J. C. 

1833. Conspectus Arachnidum, p. 14 
Thorell, T. T. 

1859. Nya exotiska Epeirider. Ofvers K. Vet.-Akad. F(3rli.. pp. 299-304. 
Walcken.^er, C. a., Baron de 

1837- Histoire naturelle des inscctes aptercs. 4 Vols. Paris. 

1847. 
(Received March 19, 1963.) 



Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. 131, Xo. 



lievised genekic diagnoses of the fossil 

fishes megalk'hthys and ectosteorhachis 

(fa:milv osteolepidae). 

By Keith Stewart Thomson 



With One Plate 



CAMBRIDGE, MASS., U.S.A. 
I'RINTEl) FOR THE MUSEUM 

JrLY 7, 1964 



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WITH THE 

MUSEUM OF COMPARATIVE ZOOLOGY 
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Bulletin of the Museum of Comparative Zoology 

II A R V A K D U N I \' K H S I 'V Y 

Vol. 131, No. !) 



KE VISED GENERIC DIAGNOSES OF THE FOSSIL 

FISHES MEGALICIITIIYS AND EOTOSTEOKHACHIS 

(FAMILY OSTEOLEPIDAE). 

By Keith Stewak'i' Thomson 



With One Plate 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

July, 1964 



Hull. Mils. Comp. ZuoL, H.-iivanl t'liiv., 131 (9) :283-311, July, 19(54 

No. 9 — Rcriscd (j( n< He diagnoses of the fossil fishes 
Megalichthys a?(f/ Ectosteorhachi.s {family Osteolepidae). 

By Kkith .Stkwakt Thomson i 



In the course of .studies on the inorpli()I()«^y of the Hhipidistia 
(fossil fishes of the order Crossopterygii) 1 liave found it neces- 
sary to enquire into the systematies of certain of the forms 
concerned, notably Ectosteorhachis and 3Ie(jaliehtJiys (members 
of tlie family Osteolepidae). 

The luime Eetosteorhaehis was coined by Cope (LSHO) foi- 
material of a rhipidistian collected in the Permian "red-beds" of 
Texas. Cope described the type species, Eetosteorhaehis nitidus, 
and later (1883) a second si)ecies, E. ciceroneiis, which he dif- 
ferentiated from E. nitidus by the nature of the surface oiiia- 
mentation of the dermal bones of the skull. Hussakof (1911j 
showed that the two forms actually belong- to the same species. 
Until recently remains of Eetosteorhaehis were rare, but now 
a considerable amount of material, particularly in the collections 
of the Museum of Comparative Zoology, is available for study. 
Eetosteorhaehis has only l)een found in the Lower Permian of 
the United States, and the principal collections have been made 
in the Wichita Group (Moran to Belle Plains formations) ; a 
single jaw in the Museum of Comparative Zoology was recently 
collected in the Dunkard Group, Lower Permian, of Clarke 
Mill, Ohio. 

In 1891 Cope decided that his genus Eetosteorhaeliis was in- 
distinguishable from the form known as " Megaliehthys" — a 
common Carboniferous genus well known in the European Coal 
Measures. In more recent times re-study of Eetosteorhaehis, as 
Romer (1941) has noted, has led to the suggestion that tliis 
form is, after all, a distinct genus. The aim of this pai)er is to 
explore this view, by a comparative anatomical study of the two 
forms; as will be seen, the conclusion reaclK^l is that Ket- 
osteorhaehis should be re-established as a valid genus. 

'^Megalichthys" is a rhipidistian occurring very commonly 
in the Carboniferovis deposits of Europe, wliei-e it is frequently 
found in the ironstone shales associated with workable coal seams, 
and less commonly in the Carboniferous of North America. Un- 
fortunately, there is considerable confusion concerning the 



1 Present address: Department of Zoolojr.v, University College, London. 



286 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

nomenclature of this genus and at the end of this paper I have 
included a discussion of this problem. The name MegalicJithys 
throughout this study is used in the sense of Smith-Woodward 
(1891) as is, in fact, the common usage of the name. 

Several species of MeyalicJithys have been described; the 
discussion of the genus given below is based mainly on the 
structure of the type species MegalichtJiys Jiihherti Agassiz. 
Mcgalichthys coccolepis Young, intcrmcdius Woodward, laticeps 
Traquair, and macropoma Cope, have been distinguished from 
M. hihhoii principally on the relative proportions of the maxillae 
and gular ])lates and such distinctions do not affect our present 
discussion in any way. 

During this study, which formed part of my dissertation for 
the degree of Doctor of Philosophy at Harvard University, I 
have been greatly assisted by Professor A. S. Eomer. I am also 
grateful to him for the use of the collections and facilities of the 
Museum of Comparative Zoology. I am indebted to Professor 
G. G. Simpson for his criticism of the final section of this paper. 
I must also thank Dr. E. I. White, Keeper of Palaeontology at 
the British Museum (Natural History), London, who allowed me 
to spend several weeks studying in his department during the 
summer of 1962. Mr. H. A. Toombs of the British Museum 
(Natural History) and Dr. C. D. Waterston of the Royal 
Scottish Museum, Edinburgh, have also given me assistance and 
advice ; I am particularly grateful to the latter for his efforts 
to identify for me various specimens from the Hibbert Collection 
in the Royal Scottish Museum. 

Dr. B. Schaeffer of the American Museum of Natural History. 
Dr. D. Baird of Princeton University, and Dr. P. P. Vaughn 
of the University of California at Los Angeles have each loaned 
me specimens from the collections of their various institutions. 

I Avas the recipient of North Atlantic Treaty Organiza- 
tion Science Studentship 3/60/955 from 1960 to 1963 and the 
Jeffries Wyman Scholarship at Harvard University during 
1960/1961 while I was engaged in this study. 

MATERIALS 

The material of Ectostcorhachis used in this study comes 
largely from the collections of the Museum of Comi)arative 
Zoology and was collected in the "red-beds" of North Central 
Texas (Wichita Group, Lower Permian). Specimens, including 
the holotype (American Museum of Natur;il History |A^IXII] 



THOMSON: MEGALICHTIIYS AM) KCTOSTEOBIIACIIIS 287 

7239), were loano(l to me by various iii.st i! ut ions as ac- 
kuowledfred above. 

Of the ^enus Mcgalichfhys, several spt'ciiiiciis in the ^liiseiiiu 
of Comparative Zooloj^^' (MCZ), including' material of the 
North American species M. macroporihd, were used in this study. 
However, the majority of the material studied is in the collec- 
tion.s of the British Museum (Natural History) (P.MXH) ; this 
includes the specimen (P. 4251(5) descrilx'd by Agassiz (1843) 
in his definition of the genus (see later for discussion of 
nomenclature). 

ECTOSTEORHACHIS 

Dermal skull roof A As is the case in other Rhipidistia, th(> 
outer enamel and dentine layers of the dermal bones of the skull 
of Ectosteorhachis, especially in the ethmoid region, tend often 
to be fused into a single covering in such a way as to obliterate 
any external indication of the sutures between separate bones 
(cf. Westoll, 1936). However, in the collections of the Museum 
of Comparative Zoology, there are many specimens (especially 
MCZ 6498, 6499, 8652," 8661 and 8668)* from which this outer 
layer has been lost due to the process of weathering of the 
fossils. It has thus been possible to give a more complete descrip- 
tion of the pattern of the dermal bones of the skull of this 
genus than may be given for many genera of Osteolepidae. 

The only published figures of the skull of Ectosteorhachis are 
those of Hus.sakof (1911), and of Cope and Matthew (1915), 
but these show few details of the dermal bone pattern. 

The premaxillary element in Ectosteorhachis corresponds to 
the bone which in certain other Rhipidistia Jarvik (1942, 1944) 
has termed a "compound" bone, comprising a true pre- 
maxilla, a rostral element which encloses the ethmoid commis- 
sure of the lateral line system, and probably also the first 
of the series of nasal bones. This element has been given the 
unwieldy name of "naso-rostro-premaxilla." Jarvik (1942. p. 
347) believes that the interpretation of such a unit as a "den- 
tigerous rostral" (cf. Westoll, 1936, 1937) is probably incorrect. 

The supi-aorbital lateral line, anterior to the parietal bone 
("frontal" of Jarvik), is borne upon a series of four separate 



1 Throughout this paper the terniinolojry used for the various dermal elements 
in the skull will follow the system of .Tarvik (1!)42, 1944) with the exception 
of the parietal and postparietal hones whicli are termed hy .Tarvik "frontal" and 
"parietal," respectively. 



288 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



nasal elements (Fig. 1) which probably represent a reduction 
from a row of six or seven nasals (cf. Osteolepis; Jarvik, 1948) 
of which the first has been incorporated into the premaxil- 
lary unit. 



eth.comm 



s.o.l . - 




Fig. 1. Ectosteorhachis. Diagrammatic reconstruction of the dermal skull 
roof in dorsal view. 



There is a pair of anterior postrostral bones and, posterior to 
these, a single median postrostral with, in some specimens, a pair 
of smaller postrostrals lying near its anterior margin, between 
the median postrostral and the second nasal element. 

The infraorbital lateral line is borne upon the lachrymal and 
thence directly on to the naso-rostro-premaxilla. There are no 
separate lateral or anterior rostral elements associated with it. 
The single external narial aperture is bounded by two small 
bones which have been termed the prenarial and postnarial 



THOMSON: MEGALHII'IIIVS AND ECTOS TKOK 1 1 ACI I IS 



289 



(Westoll, 1943). The liomology of these bones will be discussed 
in a later section. 

Beeau.se of the extent of the posti-ostral bones, the parietal 
bones occupy a relatively short part of the roof of the ethmoid 
region. There is no external parietal foramen. The dermo- 
sphenotics, postparietals, supratemporals, and tabulars are 
arranged in the normal rhipidistian way (Fig. 1). The dorsal 
margin of the orbit seems to be formed by two supraorbitals 
on each side (Fig. 1, s.o.). 

The cheek plate (Fig. 2A). The cheek plate in Ectosteorhachis 
is made up of lachrymal, jugal, postorbital and squamosal bones 
arranged in the normal rhipidistian manner. 




p,op 



Fig. 2. Schematic reconstruction of the anterior cheek-plate region. 
A, Ectosteorhachis, B, Megalichthi/.s. 



The palate (Fig. 3A). I have only studied the ethmoid 
division of the palate. The only other rhipidistian in which 
the palate has been described in detail is Eusthenopteron 
(Jarvik, 1942, 1944, 1954), a rhizodontid. The palate of Ect- 
osteorhachis differs significantly from that of Eusthenopteron. 
The vomers of Ectosteorhachis are almost triangular in shape 
and do not quite meet in the midline. Each vomer bears a pair 
of alternating tusks and an anterior ridge of marginal teeth. 
The parasphenoid seems to consist of two parts: the tooth- 
bearing ridge which reaches about halfway along the flat ventral 
surface of the endocranium, and a thin bony lamina which (as 
described by Komer, 1937) continues forw^ard and lateral to the 
ridge. The whole is fused solidly to the endocranium. The 
palato-quadrate complex is exactly comparable, as far as I am 
able to tell, with that described by Watson (1926) in 
Megalichthys. 

The conformation of the endocranial part of the palatal aspect 
of the ethmoid division of the skull is shown in Figure 3A. 
A major point of interest is the configuration of the anterior 



290 



BULLETIN : MUSEUM OF COMPARATR'E ZOOLOGY 



palatal recesses (Fig. 3A, a.p.r.). These are shallow pits Ijnng 
between the anterior margin of the endocraniuni and the over- 
lying dermal bones ; they are separated from each other by 
posterior medial expansions of the premaxillary bones where 
each bone bears a stout tusk. When the lower jaws were oc- 
cluded (as seen in specimen MCZ 9830), these anterior recesses 
served to receive the tips of a pair of large tusks at the anterior 
ends of the lower jaw rami (ef. Thomson, 1962). 




Fig. 3. Ethmoid region of tlie palate. Ventral view. A, Eciosteorliachis, 
B, Megalichihys. 



The lower jaws (Fig. 4, A, B, C ; based mainly on specimens 
MCZ 8641, 8826, 8827). As may be seen in Figure 4A, the outer 
aspect of the lower jaw does not differ greatly from that of 
MegalichtJiys (as figured by Watson, 1926). It is made up of 
the dentary and four infradentary elements — splenial, post- 
spleiiial, angular, and surangular. These elements are ap- 
proximately demarked by grooves in the shiny continuous enamel 
covering on tlie dermal bones (Fig. 4A, gr.). 



THOMSON: MEGALICHTIIYS AND ECTOSTEORIIACHIS 



291 



The inner surfaee of the lower jaw is made up of the foUowinj^' 
elements: deutary, three coronoids, preartieular and articular 
(Fi<?. 4, B, ('). The deiitary bone bears, at the antei-ior tip of 
the jaw, a large tusk, replaced in an alternating manner (Fig. 
4, B, C, dJ.), and behind this a broad ridge — which I have 
termed the crista dcntalis (Fig. 4, B, C, cr.d.). The crista 
dentalis is covered witii small denticles and seemingly serves to 
occlude with a ridge of teeth on the anterior margin of the 
vomer. The crista dentalis is formed as an enlargement of the 
anterior rim of the anterior dentary fossa (Fig. 4B, a.d.f.) — 
a large pit for the reception of the vomerine tusks. 

The preartieular covers a large part of the inner surface of 
the jaw (Fig. 4B, pr.art.) and also plays a large role in the 
formation of the jaw symphysis. A concave facet on each 




cri sta dental i s 





Fig. 4. Ectosfeorhacliis. Lower j;iw. A, lateral view of the left ramus. 
B, inner view of right ramus. V, oct'lusal view of riulit rauuis. 



292 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

surface of the symphysial region (Fig. 4B, s.mb.) must have 
contained a small mental bone such as has been described in 
many Rhipidistia. 

The gular series, as depicted by Hussakof (1911, fig. 53), 
comprises a pair of j^rincipal gulars, an anterior median gular, 
and on each side a row of six lateral gulars. 

MEGALICHTHYS 

Dermal skull roof. The dermal bones of the skull of Mega- 
Uchthys have been described in part by many authors, but 
due to the problem of the coalescence of the outer layers of the 
dermal bones, many details, especially of the ethmoid region of 
the skull roof, have never been described. Miall (1884), Tra- 
quair (1884), Wellbourne (1900), Birks (1914), and Moy- 
Thomas (1935) have all added in some way to the original 
description of the skull by Agassiz (1843). Moy-Thomas' figure 
of the skull (1935, fig. 1) is the most complete restoration. 
Holmgren and Sten.sio (1936, fig. 272 C) figured the anterior 
region of the snout of a specimen in the British Museum (Natural 
History), number P. 7875 (not P. 1878 as quoted by Holmgren 
and Stensio), a new drawing of which is presented here (Fig. 
6E). This specimen shows the arrangement of the dermal bones 
of the snout very well, since weathering of the fossil has exposed 
the sutures between the separate bones. 

There is some variability in the arrangement of the smaller 
elements in the snout region of Mcgalichthys. Figure 6 shows 
the pattern of the dermal bones in six of the specimens (BMNH 
P. 7729, P. 7842, P. 7846, P. 7878, P. 7886, 21421) which have 
been used to derive what I consider to be the typical condition 
(Fig. 5). 

The premaxillary unit is a naso-rostro-premaxilla, as in 
Ectosteorhachis. The supraorbital lateral line is carried from 
the parietal bone to the nasal area of the premaxilla by a row 
of nasal elements, of which five seems to be the typical number 
(cf. PL 1). Fusions of the nasals may occur (Fig. 6), most 
commonly between nasals 2 and 3, and nasals 4 and 5. 

The most anterior of the nasal elements on each side is a 
large bone whieli might be interpreted as being fused with a 
more median anterior postrostral bone (Fig. 5, n.prf). There is 
a pair of posterior postrostral bones which may also merge 
witli nearby nasals (Fig. 6F). In certain cases a median posterior 



THOMSON : MEGALICIITHYS AND ECTOSTEORIIACIIIS 



293 



postrostral bone may he i)resent between the posterior post- 
rostrals (Fipr. 6F, m.pr.). 

The infraorbital lateral line passes directly from the lachrymal 
to the naso-rostro-premaxilla and has no connection with the 
bones .snrronnding the external naris. The external naris is 
bonnded by two bones, an anterior prenarial bone wliieh is very 
large, and a smaller postnarial (Fig. 5, pr.n., p.n.). 

The parietals are relatively long, compared with Ect- 
osteorhachis; they lack the external parietal foramen. AVith 
regard to the rest of the dermal sknll roof I have been able to 
add little to Moy-Thomas' description (1935). 




Fig. 5. Megalichtliys. Diagrammatic reconstruction of the dermnl skull 
roof in dorsal view. 



294 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



The cheek region (Fig. 2B). The arrangement of the 
lachrymal, jugal, postorl)ital and squamosal bones in the cheek 
region is essentially similar to that of Ectosteorhachis. 




Fig. (i. A - F. MciiaUchthy.^. Skeiclies of six spceinunis sliowiiip: nrriniKO- 
ineiit of the doniial Ijoiies of the ctlinioid division of the skull. Dorsal 
views. A, RMNH P. 7846; B, BMNII P. 7842; C, BMNII P. 77l:9 ; 1), 
BMNIl L'14L'l; E, BMNH P. 788(i ; P, BMNH P. 7878. 



THOMSON: MEGALKMITIIYS AND ECTOSTEORHACHIS 295 

The palate (Fig. 3B). The otlmioid region of tlie palate is 
remarkably similar to that of Eclostcorhachis. In Mcgalichtliys 
the anterior i)alatal recess is also divided into two parts by the 
bases of the premaxillary tusks, and in addition, by a .short 
anterior projection of the median segment of the anterior margin 
of the endocranium, which abuts against the premaxillae. (See 
Fig. 3B, a.c.c.) 

The tooth-bearing ridge of tiie parasphenoid is long, reaching 
almost to the very tip of the endocranium. It has not been 
possible to establish whether or not there is an anterolateral 
extension of the parasplienoid corresponding to that of Ect- 
ostcurhachis. The vomers (Fig. 3B, v.) are of roughly triangular 
shape; they approach each other in the midline in the region 
of the tip of the parasphenoid. There is a pair of alternating 
tusks on each vomer; the anterior margin of the vomer is not 
strongly denticulate. 

The lower jaws. The lower jaw of Megalichthys was described 
by Watson (1926, figs. 37, 38) ; a few very minor modifications 
must be noted. I have been able to confirm, from specimens (e.g. 
nos. P. 7886-7888 in the Britisli Museum (Natural History), 
that there are three coronoid bones in Megalichthys (Watson 
had noted tliat the posterior of the two coronoids he figured 
might be double). The adductor fossa is rather wider, and the 
prearticular bone somewhat more narrow than is shown in 
Watson's figures. The crista dentalis is absent. 

The gular series, as depicted by Moy-Thomas (1935, fig. 3) 
for example, consists of a pair of principal gulars, an anterior 
median gular, and six pairs of lateral gulars. 

DISCUSSION 

There can be no doubt that Ectosteorhachis and Megalichthys 
are closely related and have evolved either one from the other 
or together from the same (Devonian) osteolepid. Bystrov 
(1950) was of the opinion that Megalichthys is a direct de- 
scendant of Osteolepis. The principal purpo.se of this study is 
to set down the diagnostic differences between Ectosteorhachis 
and Megalichthys, but in order fully to understand the character- 
istic features of these fishes it will be necessary to refer to the 
Osteolepidae of the Devonian. 

I have not been able to bring to light any significant dif- 
ferences in the patterns of the dermal bones of the posterior 



296 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 

part of the skull roof between Ectostcorhachis and McgalichtJiys, 
although both differ from the other Osteolepidae in having only 
two extrascapular bones. There are very characteristic dif- 
ferences between the two genera in the pattern of the dermal 
bones of the ethmoid region — differences which, incidentally, 
help to clear up a twenty-year old confusion concerning the 
homology of the various bones in the narial region. 

The composition of the naso-rostro-premaxilla seems to be 
the same in both Ectosteorhachis and Megalichthys. The nasal 
series is essentially the same in both genera; the number of 
separate nasal elements may be reduced by fusions, but there 
seem to have been, basically, tive nasals, excluding the one 
incorporated into the premaxillary complex. 

The parietal bones in Megalichthys are proportionately longer 
than in Ectostcorhachis ; this seems to be associated with the 
corresponding increase in the size of the postrostral elements in 
the latter genus. The pattern of the postrostral elements seems 
to have been derived from that of a form such as Osteolepis (cf. 
Fig. 7A) in which there was but a single postrostral element 
situated between the rear nasals. In Megalichthys there is a 
pair of postrostrals in this position and the anterior nasal bones 
are enlarged mesially. In Ectosteorhachis the anterior nasal 
bones are small and lie lateral to a pair of anterior postrostrals 
which have the appearance (cf. Figs. 1 and 5) of having been 
divided off from the mesial part of the anterior nasals of a 
form like Megalichthys. Posterior to these, in Ectosteorhachis, 
there is a single, median and large posterior postrostral bone 
corresponding exactly with the single postrostral bone of 
Osteolepis (cf. Figs. 1 and 7A). The arrangements of these 
bones in Ectosteorhachis and Megalichthys would seem to 
indicate that these genera have evolved independently from a 
Devonian ancestor ; however, the judgment of Westoll concern- 
ing such bones is that they are anamestie bones and therefore 
of limited phylogenetic significance. 

In order to interpret the significance of the pattern of the 
bones around the external naris it is necessary to refer to the 
arrangement of these elements in Osteolepis (Fig. 7A), as it has 
been described by Jarvik (1948). In Osteolepis the external 
naris is bounded ventrally by a single element — the lateral 
rostral — which is a true rostral element {sensu Jarvik), con- 
taining a segment of the infraorbital lateral line in its passage 
from the lachrymal to the premaxilla. The external naris is 



THOMSON: MEGAMCIITIIYS AND ECTOSTKORIIACHIS 



297 



bounded by two small deriiuU bones, sometimes fused into a single 
element, whieb are termed tbe anterior teetals. Tiiese three 
eircumnarial bones fit in between the na.sal series and the com- 
pound premaxilla. Posteriorly they are bounded by the 
lachrymal, which may slightly underly the lateral rostral, and 
the supraorbito-tectal, which lies between the posterior of the 
anterior teetals and the anterior of the two supraorbitals. 





Fig. 7. A, Skull roof of Osteolepis (from Jarvik, 194S, fig. 16a). B, 
Restoration of the ethmoid division of the palate of a Devonian 
" osteolepid." (Comijosite of Osteolepis and Glyptopomus.) 



The situation in the post-Devonian Osteolepidae is rather 
different. In MegaUchthys the external naris is bounded by two 
elements — a larger prenarial and a smaller postnariaH. As 
shown in Figure 5, the larger prenarial bone bound.s the narial 
opening in front and it extends both dorsally and ventrally of 
the naris. There is no connection of this bone with the lateral 
line system. The postnarial Ls small and bounds the naris 
posteriorly. The prenarial is bounded by the nasals, the naso- 
rostro-premaxilla, the postnarial and the lachrymal. The post- 
narial is bounded by the nasals, the anterior supraorbito-tectal, 
the lacbrymal and the prenarial. The lachrymal bone makes 
contact with the premaxilla, and the infraorbital lateral line 
passes directly between these bones. 



lit should be noted that Westoll's tigiires of the snout of Megalichthiis (104.3. 
fig. 8, c and d), showing prenarial and postnarials of equal size, seem to have 
been restored after the condition in Ectosteorhachis. 



298 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

In EctosteorJiachis the narial aperture is bounded by prenarial 
and postnarial bones having exactly the same relations to the 
other bones of the ethmoid region as in Mcgalichthys. The pre- 
narial bone, however, is a small bone of the same size as the 
postnarial. The small size of the prenarials seems to be com- 
pensated for by the large size of the anterior postrostral bones 
which are not present in Megalichthys. 

There is some confusion in the literature concerning the 
homology of the.se circumnarial elements. Jarvik considers the 
situation in Osteolcpis to be primitive and has also concluded 
from his studies that the lateral rostral bone of this form cor- 
responds to the septomaxilla of the tetrapods (1942). We,stoll, 
on the other hand, has considered the situation in Megalichthys 
and Ectosteorhachis, with pre- and postnarial bones, to be 
primitive. He believes that the postnarial bone, which he states 
to be typically present in all Rliipidistia (1943, p. 90), is the 
homologue of the tetrapod septomaxilla. Westoll also considered 
that the lateral rostral bone of Devonian Osteolepidae and 
Rhizodontidae did not have a primary relationship with the 
infraorbital lateral line canal. 

All the evidence that I have collected during this study seems 
to indicate that Megalichthys and Ectosteorhachis have evolved 
from typical Devonian Osteolepidae, and the nature of the cir- 
cumnarial bones serves only to emphasize this view. The position, 
shape and size of the prenarial bone of Megolirhthys indicate 
that this element has been formed from the merging of a 
lateral rostral and the more anterior member of a pair of anterior 
tectals of a form such as Ostcolepis, so that the "new" element 
encloses the naris from in front. In Ectosteorhachis the prenarial 
is small and we may suppose the decrease in size as compared 
with Mcgalichthys is associated with a reduction of the anterior 
tectal component of the prenarial bone. The nature of the pre- 
narial bone in Ectosteorhachis may thus be interpreted as 
evidence suggesting that this genus has been evolved from 
Megalichthys itself. 

The postnarial bone in both Megalichthys and Ectosteorhachis 
seems to correspond to the more posterior of the anterior tectals 
of a form such as Ostcolepis, which, with the shifting forwards 
of the lateral rostral element, has moved ventrally to enclose the 
naris from behind. 

Although the arrangement of the circumnai-ial bones in 
Megalichtttys and Ectosteorhachis may thus be considered to 
have been secondarily derived from that of Devonian forms, 



THOMSON: MEGALICIITIIYS AND ECTOSTEORIIACIIIS 299 

the iiaiiic '' i)ri'iiai'ial " (Westoll, 1943) must be retained for 
these two genera sinee it won hi be inaccurate to consider this 
element to represent solely the lateral ro.stral bone. Similarly 
the nami' '* postnarial" is to be i)i'eferred to "anterior teetal" 
since this bone does not have the same relations with the sur- 
rounding bones as it does in the Devonian Osteolepidae. 

The supraorbital series was rarely preserved in the material 
available to me, but seems to have consisted of two elements as 
in most Rliipidistia (cf. Westoll, 1943). 

The cheek region. As shown in Figure 2, the anterior part 
of the cheek region is es.sentially the same in both genera. The 
maxilla and s(iuamosal are slightly longer in EctosieorJtachis 
than in McgalicJithys. 

The palate. The ethmoid division of the palate is very similar 
in the two genera (see Figure 3). Division of the anterior 
palatal rece.ss into two portions is effected by an expanded part 
of the premaxilla on either side of the midline in Ectosteorhachis. 
In M( (jaJicJifhif.'i there is, in addition, a short "buttress" from 
the anterior part of the endocranium. 

The tooth-bearing part of the parasphenoid is much longer in 
Megalichthys than in Ectosteorhachis. In the former genus it 
reaches to the anterior tip of the endocranium and touches the 
median extremities of the vomers. In Ectosteorhachis the tooth- 
bearing ridge of the parasphenoid ends far posteriorly and there 
is no contact with the vomers. 

The anterior rim of the vomers in Ectosteorhachis is more 
prominently toothed than in Megalichthys. 

The lower jaws. There is little difference to be observed be- 
tween the two genera with respect to the outer surface of the 
lower jaw rami. In Ectosteorhachis the grooves in the outer 
surface of the enamel contain "pit-organs" which are lacking 
in Megalichthys. 

With respect to the inner surface of the lower jaw rami, there 
are greater differences between the two genera. The adductor 
fossa is longer and a little wider in Ectosteorhachis than in 
Megalichthys (in the former the adductor fossa takes up about 
four-tenths of the total length of the jaw; in Megalicht]n;s 
about three-tenths). Tlie crista dcntalis, present in Erfoslio- 
rJiachis, is lacking in Megalichthys. 

Compariscjn with other Osteolepidae. We have seen above 
that the jiattern of the dermal l)ones of the snout ol' Ect- 
osteorhachis and M( (jalichthys (the only non-Devonian members 
of the family Osteolepidae) may readily be derived from that 



300 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

of a form such as Osteolepis; unfortunately the other Devonian 
members of this family are less well known (ef. Jarvik, 1948, 
1950). 

The palate of Glyptopomns as revealed in dorsal view only, 
ha^ been described by Jarvik (1950, fig. 6). By combining 
details from this description and from specimens of Osteolepis 
in the Museum of Comparative Zoology (nos. MCZ 8737, 5875), 
I have been able to derive a highly tentative reconstruction of 
the ventral surface of the palate of an hypothetical generalised 
Devonian "osteolepid" (Fig. 7B) . The vomers are of the roughly 
triangular shape seen in the later forms, and have a slightly 
wider region of contact in the midline. The tooth-bearing ridge 
of the parasphenoid is very long and thin, extending along the 
whole length of the ethmoid endocranium. It is interesting to 
note the progressive shortening and broadening of the tooth- 
bearing ridge in the sequence "Devonian osteolepid" to Mega- 
lichthys to Ectosteorhachis. 

The crista dentalis seems to be a specialised feature of 
Ectosteorhachis. The only other genera in which it has been 
reported are Panderichthys (Gross, 1941, fig. 22), which has 
a few small denticles in this position, and Litoptychius (Denison, 
1951, fig. 46), which, although it has been described as a 
rhizodontid^, may thus have features in common with the 
Osteolepidae. 

CONCLUSIONS 

The results of this study have been to show that the Permian 
rhipidistian of North America known as Ectosteorhachis is gen- 
erieally distinct from the Carboniferous genus known as Mega- 
lichthys which occurs in both Europe and North America. 
The two genera are very closely related to one another and the 
evidence of the circumnarial bones in the snout seems to demon- 
strate that Megalichthys evolved from a Devonian osteolepid 
and that the genus Ectosteorhachis separated from McgalicJithys 
at a later date. The evidence from the postrostral bones might 
be interpreted as indicating that the separation between Mega- 
lichthys and Ectosteorhachis occurred before the pattern of 



iDenisoii ilcsT-ribed LitoptychiiiN ;is :i iiii'inhi'r cil' the I'.iMiily Kliizdddiit iil;u', 
but Orvig (1!).")7) expressed the opiiiiuii that it is a iiifiiiliiT ol' tlie IIi)h)iit.v<-lii(hie 
(basing his argiinient on the structure of the scab's). However, the syinphysial 
region of the lower jaw of LitD/il iicliiiiK bieks the iiarasynipliysial tooth whorls 
which are now (Jarvik, lyiil!) said to be typical of the Holoptyehidae and 
I'orolepidae. 



THOMSON: MEGALICHTIIYS AND ECTOSTEOBHACHIS 301 

tlu'se ('Iciiiciits had becoiiic staMliscd ; hiil this is not borne out 
by the teiu])oral distrii)iition of tht' fossils. The <i'eiius Mcga- 
lichthys oeeiirs in the Carboniferous of both Eurojx' and North 
Aineriea, but Ectosi(<irh(icliis has only been found in the Ijower 
Permian of North America. 

In partial summary of the aimtondeal evifh'uee discussed in 
the preceding pages, I present amended generic diagnoses of 
Megalichthys and Ecfosteorhachis. 

Order CROSSOPTERYGII Cope, 1872 

Suborder RHIPIDISTIA Cope, 1887 

Family OSTEOLEPIDAE Smith-Woodward, 1891 

Genus MeGALICHTHYS Agassiz, 1843 

Type species: Megalichthys hibberti Agassiz, 1843. 

To the list of synonyms given by Smith-Woodward (1891) 
must be added : 

Parabatrachus Owen, 1853: Hay, 1902, p. 362; Berg, 1958, 
p. 92. 

Catixkeus Whitley, 1940, p. 242. 

Occurrence: Carboniferous of Europe and North America. 

Amended diagnosis (cf. Smith-Woodward, 1891) : Dermal 
bones of the skull arranged as in Osteolepis with the following 
exceptions. The external naris is surrounded by a very large 
prenarial bone and a smaller po.stnarial bone. The lateral rostral 
bone is not present as an independent unit and the infraorbital 
lateral line canal passes directly from the lachrymal bone to the 
premaxilla. There are no independent anterior postrostral bones ; 
the posterior postrosti'al is paired. There is no parietal foramen. 
There are two extrascapulars. The vomers are triangular in 
shape and bear two tusks replacing each other alternately. The 
anterior margin (of the vomer is not prominently toothed. The 
tooth-bearing ridge of the parasphenoid reaches as far anteriorly 
as to touch the median tips of the vomers. All teeth are rounded 
in cross-section. 

The vertebrae are ossified as narrow rings and the neural and 
haemal arches are fully developed. 

The scales are more or less smooth and punctate. The tail 
is heterocercal, tending towards diphycercal. The pectoral fins 
are set rather far back ; their bases are covered with scales, as 
are those of the pelvic fins. The anterior dorsal fin is set slightly 



302 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

in advance of the pelvic fins and the posterior dorsal fin opposes 
the anal fin. 

Megalichthys hibbeeti Agassiz, 1843 

Lcctotype (here selected i) : BMNH no. P. 42516. Skull and 
partial trunk. 

Comments: I have no new information to add to Smith- 
Woodward's diagnosis (1891) of this species. 

Genus ECTOSTEORHACHIS Cope, 1880 

Type species: Ectosteorhachis nitidus Cope, 1880. 

Previous authors have thought that this genus is a synonym 
of the following : 
Megalichthys Agassiz, 1843: Cope, 1891, p. 457; Hussakof, 1911, 

p. 168. 
Parahatrachus Owen, 1853: Hay, 1899, p. 788; Hay, 1902, p. 

362; Berg, 1958, p. 92. 

Occurrence: Lower Permian of North America. 

Amended diagnosis (cf. Hussakof, 1911) : Dermal bones of the 
skull arranged in the manner of Osteolepis, with the following 
exceptions. The naris is surrounded by prenarial and postnarial 
bones of equal size. There is no separate lateral rostral bone 
and the infraorbital lateral line passes directly from the 
lachrymal to the compound premaxilla. There is a pair of 
anterior postrostral bones and a single, large, median posterior 
postrostral bone. There are two extrascapulars. The vomers are 
triangular with a pair of alternating tusks. The anterior margin 
of the vomer is prominently toothed. The tooth-bearing ridge 
of the parasphenoid does not reach so far anteriorly as to meet 
the median tips of the vomers, but ends at the level of the 
pusterior wall of the nasal capsule. 

The dentary bone of the lower jaw overlaps the prearticular 
bone in the symphysial region, as a denticulate ledge — the 
crista dentalis. 

The scales are smooth and punctate. The tail is intermediate 
between the heterocercal and diphycereal conditions. Tbe 
pectoral fins are set rather far back. The anterior dor.sal fin is 
inserted in advance of the pelvic fins and the posterior dorsal 
fin opposes the anal fin. 

iSee below, discussion of nomenclature. 



THOMSON : MEGALICHTIIYS AND ECTOSTEORIIACIIIS 303 

EcTOSTEORHACHis NiTiDrs Cope, 1880 

Type: AMNII no. 723f). Skull and anterior scales. 
Diagnosis: As for the <:('nus. Tliis is llic only known species 
of Ectosteorhachis. 

TPIE NOMENCLATURE OF MEGALICHTUyS 

The history of the nomenclature of the genu.s Megalichthys is 
rather complicated. The genus was named by Agassiz in a paper 
(Ilil)bert, ]8;]5b) published by Ilibbert in 1835^ for remains 
of a large "sauroid" fish tliat had been discovered in the 
Carboniferous limestone quarry at Burdiehouse near Edinburgh. 
The remains of this "large fish" had been previously mentioned 
in various contexts (such as the report of Hibbert to the Geolog- 
ical Section of the British Association for the Advancement of 
Science, in 1834 [published 1835], and in Agassiz 's address to 
the same meetings). But these instances do not constitute 
definite "indication" in the sense of the 1961 International 
Code of Zoological Nomenclature. Hibbert 's was the first 
scientific account and the first proper description. 

The remains consisted of some large teeth, some smaller 
teeth, and .scales of assorted sizes. These specimens had been 
shown, during the 1834 British Association meetings, to Agassiz 
who was then in Great Britain collecting material for his "Pois- 
sons Fossiles." At the time there was a controversy in scientific 
circles about Avhether such remains were sauroid (i.e. resembling 
reptiles) or saurian (actually pertaining to reptiles). Agassiz 
and Buckland decided to settle the matter and, subsequently 
visiting various public museums in England, they found in 
the Leeds Museum a rather complete head and part of the trunk - 
of a sauroid fish from the Yorkshire coalfields. This, ihey 
decided, was identical with the Burdiehouse material. The prob- 
lem of the nature of the Burdiehouse remains was thus solved 
and "... after M. Agassiz had . . . established that these teeth 
and certain other osseous remains of Burdiehouse belonged to 
a sauroid fish ... he considered it a.s a new genus to which he 
gave the name of Megalichthys; and to the species found at 
Burdiehouse he added the name of Megalichthys hihherti." 
(Ilibbert, 1835b, p. 202.) 



1 Volume 13 of the Transactions of tlie Royal Society of EflinbnrKh. whevo the 
paper appeared, was issued between IS.'U and 1S36. Hibbert's paper (according 
to Neave, 1040) was published in February IS."?."). Most authors (e.j?. Smith- 
Woodward, 1891) have piven thi' date ns TH'Afi. 

2 Now in the British Museum (Natural History) No. P. 42.516. 



304 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Fleming in October 1835 described some remains ^ of Mega- 
lichthys hibbcrti- under the name of Ichthyolithus clack- 
manensis. 

In 1837 Sir Philip Grey Egerton, in a revised catalogue of the 
collections of himself and Lord Cole, uses the name Holoptychius 
hibbcrti in addition to the name Megalichthys hibbertii^ for 
specimens in his possession from Burdiehouse. Egerton cites 
"Agiissiz mss" as his authority for the former name. Also in 
1887, Buckland uses the names Holoptyclms^ and Mcgalichfhys 
and the authority for this, although not stated, was probably also 
"Agassiz mss" since most of Agassiz's friends in Britain seem 
to have had access to Agassiz's notes and intentions in advance 
of publication. 

Buckland, however, has confused the picture somewhat: in 
the text of his work (1837, vol. 1, p. 275) he states that "plate 
27, figures 11, 12, 13, 14, represent teeth from . . . the fishes 
. . . referred by M. Agassiz to a new genus Megalichthys." In 
the explanation of the plates appearing in volume two of the 
same work Buckland states that "plate 27, figures 11, 13, 14" 
are Holoptychus (sic) hibberti and "figure 12" is Megalichthys 
hibberti (p. 43). The acknowledged source of the figures is 
Hibbert's (1835) treatise. 

Whatever the reason for this confusion, and regardless of 
what Buckland actually intended to state, the fact remains that 
someone, probably Agassiz himself, had recognised that the 
Burdiehouse remains represented two dififerent fishes. In 1840 
Owen made this distinction formal by applying to the larger 
teeth from Burdiehouse the new generic name Rhizodus. But 
Owen states that the new genus Rhizodus is named to replace 
Holoptychius hibberti Agassiz, and presumably, since Owen did 
not name a type species of Rhizodus, he assumed it would simply 
take over the specific name of "Holoptychius" hibberti Agassiz. 
Unfortunately, Owen's authority for the latter name must have 
been an unpublished Agassiz manuscript for the name does not 
appear in "Poissons Fossiles" until 1843, when Agassiz merely 
cites the name, in a list, as "Holoptychius hibberti Owen 
(Rhizodus), Burdiehouse." The specimens concerned are the 



1 Now in the Royal Scottish Museum. Edinbuirli, No. 10.50. .S8.. 58. 
- '•Mci/dliclitlnix" in the sensp of tliis piiin-r. 

■"• 'i'hc sin'llint: of the speeitic name liililiryll or liihiicrtii sei'tiis to have varied 
witli tlie preference of the author. 

4 Ai>pnrentl.v a misprint for Holoiit iichiiiK. 



THOMSON: MEGALICHTIIYS AND ECTOSTKORIIACIIIS 305 

large teeth and scales from Burdiehouse (figured by Hibbert 
and Buckland, see Table 1) as well as the specimen figured by 
Owen (local it}' unknown). 

Agassiz finally (1843) described the "Leeds Head" specimen, 
as it ha.s become known (and other material which he considered 
to belong to the species M. falcatns), but he did not mention 
whether or not he still considerd any of the Burdiehouse material 
to belong to the genus Mcf/ulicJithys. In fact he states only that 
the localities of Megalichthys are numerous, "on en a decouvert 
dans le pays de Galles, dans les environs de Manchester, pres 
de StafiPord et dans les environs de Glasgow." This list may 
by no means be considered complete, since the actual specimen 
Agassiz was describing came from Yorkshire. 

In 1853 Owen described as a new amphibian, Parahatrachus 
colei, a specimen which later (Young, 1868) was shown to be 
the maxilla of Megalichthys hibbcrti {scnsu Agassiz). 

M'Coy (1855) seems to have been the first to realize the 
anomaly in the nomenclature of Rhizodns and Megalichthys. 
He noted that, in disregard of the facts of the case, the "Leeds 
head" was considered to be the type of Megalichthys hibberti 
and the Burdiehouse specimens were considered to belong to 
Ehizodus hibberti. M'Coy decided "against my better judg- 
ment" to "leave it as it is." 

There is little doubt that the name Megalichthys was originally 
intended to describe the "big-fish" of Burdiehouse wdiich is now 
known as Rhizodus. However, there is similarly no doubt that 
when Hibbert used the name Megalichthys hibberti he meant it 
to apply to the Burdiehouse remains — the "teeth and certain 
other osseous remains" mentioned above, and these remains, 
which included both "Rhizodus" and "Megalichthys" were 
the true types of Megalichthys hibberti Agassiz in Hibbert 1835. 

Thus Traquair (188-4) noted that the Burdiehouse material^ 
still remaining in the genus Megalichthys has priority concern- 
ing the specific name hibberti, but, having concluded that the 
Burdiehouse remains of Megalichthys are "different specifically" 
from the "Leeds head" specimen, and acquiescing to the popular 
conception that the latter forms the type specimen of Megalich- 
thys hibberti, he described the Burdiehouse Megalichthys 
with the aid of new material collected there by Hugh Miller, as 
the new species Megalichthys laticeps. 

1 "Scalos and lionps . . . nctnally fipurpil nnclor that name (^[. hihhrrti) nlona 
rrith (niv italics, KST) rnnains of Rhi::riftiix l)v I»r. Hibbert" (Traquair. 1884, 
p. 118). 



306 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

The position taken by M'Coy and Traquair has been accepted 
by Smith- Woodward in his "Catalogue of Fossil Fishes" and 
by many subsequent authors (not, however, by all, see Hay, 
1902; Jordan, 1923; Berg, 1958). 

There seems no merit in proposing that Rhizodus hibherti 
Owen be renamed Mcgalichthys hihherti Agassiz in Hibbert 
1835; similarly there seems no merit in the proposition that the 
genus now known as Mcgalichthys Agassiz 1843 be renamed 
Farahatrachus Owen 1853, with type species clacJananensis 
Fleming 1835. The common usage has remained unchanged since 
at least 1855, and has been adopted by no less authorities than 
Agassiz himself and Smith-Woodward. I propose, therefore, to 
invoke Rule 23b of the International Code of Zoological Nomen- 
clature, and formally to request the Commission to stabilise the 
status quo of Smith- Woodward's "Catalogue" (volume 2, 1891) 
on the subject. I propose that the "Leeds head" (BMNH no. 
P. 42ol6) be adopted as the lectotype of Megalichthys hihderti 
Agassiz 1843, and that the large mandibular tooth figured by 
Hibbert (1835b, pi. 9, fig. 2) now in the Royal Scottish Museum 
(no. 1950.38.63) be adopted as the lectotype of Rhizodus hihherti 
Owen 1840, in place of the specimen originally figured bj' Owen 
and which is now lost. 

As a summary of the history of the nomenclature of the 
Burdiehouse specimens, I have drawn up the following table : 

Table 1 

The Burdiehouse specimens 

All originally described by Hibbert (1835, pi. 8, figs. 1 to 6, pi. 9, 

figs. 1 to 10, pi. 10, figs. 1 to 3, pi. 11, figs. 2 to 8) as Megalichthys hihherti 

Agassiz. 

now known as Rhizodus now known as Megalichthys 

1. Egerton (1837) from Agassiz Egerton (1837) from Agassiz 
MS " Holoptychius hibhrrti" (1835) "Megalichthys hibhcrtii" 

2. Buckland (1837, pi. 27, figs. 11, Buckland (1837, pi. 27, fig. 12 from 
13, 14, from Hibbert, 1835, pi. 9, Hibbert, 1835, pi. 9, fig. 10) as 
figs. 2, 3 and 8) as ' ' ITolnptjictnis "Megalichthys hihherti" 
hihherti" 

3. Agassiz (1843) as "Holnpty- Agnsniz (1843) as " Megalichthys" 
chilis hihherti Owen, (Bin sod us)" 

4. M'Coy (1855) as "Rhizodus M'Coy (1855) as " Fhi-ndus hih- 
hihherti" herti" 

5. Tra(|uair (1884), actual speci- 
mens not cited. Rcnauied "Mega- 
lichthys laticeps" 

6. Smith-Woodward (1891) lists Smith-Woodward (1891) lists Hib- 
Ilibbert's pi. 8, fig. 1, pi. 9, figs. bert's pi. 11, figs. 2 to 8, as 
2, 3, 9, 10, as "Rhizodus hih- " Megalichthys laticeps" 
hrrii"; TTibberi 's pi. 8, fig. 2 as 

' ' Rh i sod us orna f us ' ' 



THOMSON: .ME(iALI(IITIlVS AXI) KCTOSTEORITACIIIS 307 

LITIOKATUKE CITED 

Aqassiz, J. L. R. 

1835. On the fossil fishes of Scotland. Hop. Brit. Assoc. Adv. Sci., 

Edinburgh, 4: 646(547. 
1843. Keeherches sur les poissons fossiles. Neuchatcl and Soleure, 
vol. 2, 310 pp. 
Berg, L. S. 

19.18. System der rezenten und fossilcn Fischartigen und Fische. 
Deutscher A'erlag, Berlin, 310 pp. 
BiKKS, S. (j. 

1914. Mf'cjuUrhtlnjs : a study incorporating the results of work on 
previously undescribed material. Trans. Nat. Hist. Soe. North- 
umberland Durham Newcastle, (n.s.) 4: 307-329. 

BUCKLAND, W. 

1837. Geology and mineralogy considered with reference to natural 
theology. 1st ed. London, 2 vols., 552 pp. 
Bystrov, a. p. 

1950. Microscopic structure of the bones and teeth of the Carbonifer- 
ous crossopterygian fish Alegalichthys (family Osteolepidae). 
Dokl. Akad. Nauk. U.S.S.E., 34: 119-121. (In Eussian.) 

Cope, E. D. 

1880. Second contribution to the history of the Vertebrata of the 

Permian formation of Texas. Proc. Am. Phil. Soc, 19: 38-58. 
1883. Fourth contribution to the history of the Permian formation 

of Texas. Proc. Am. Phil. Soc, 20: 628-636. 
1891. On the character of some Palaeozoic fishes. Proc. U.S. Nat. 
Mus., 14: 447-463. 
Cope, E. D. and W. D. Matthew 

1915. Hitherto unpublished plates of Tertiary Mammalia and Permian 
Vertebrata. Am. Mus. Nat. Hist., Monograph series, 2. 

Denison, R. H. 

1951. Late Devonian fresh-water fishes from the Western United 
States. Fieldiana, Geology, 11 (5): 221-260. 

Egerton, P. DE M. G. 

1837. A systematic and stratigraphic catalogue of the fossil fishes 
in the cabinets of Lord Cole and Sir Philip Egerton; together 
with an alphal)etical and stratigraphical catalogue of the same 
species, with reference to their published figures and descrip- 
tions. Rev. ed., London, 20 pp. 
Fleming, J. 

1835. Notice of the remains of a fish found in connection with a bed 
of coal at Clackmannan. Edinburgh New Philos. Jour., 19: 
314-316. 
Gross, W. 

1941. Uber den Unterkiefer einiger devonischer Crossopterygier. Abh. 
Preuss. Akad. Wiss., math.-nat. Kl., 7: 1-51. 



308 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Hay, O. p. 

1899. On some changes in the names, generic and specific, of certain 

fossil fishes. Amer. Natural., 33: 783-792. 
1902. Bibliography and catalogue of the fossil Vertebrata of North 

America. Bull. U.S. Geol. Surv., 179: 1-868. 

HiBBERT, S. 

1835a. On the ossiferous beds contained in the basins of the Forth, 
the Clyde, and the Tay. Rep. Brit. Assoc. Adv. Sci., Edinburgh, 
4: 642-644. 
1835b. On the freshwater limestone of Burdiehouse, in the neighbour- 
hood of Edinburgh, belonging to the Carboniferous group of 
rocks. With supplementary notes on other freshwater lime- 
stones. Trans. Roy. Soc. Edinburgh, 13: 169-282. 
Holmgren, N. and E. A. Stensio 

1936. Kranium und Visceralskelett der Akranier, Cyclostomen und 
Fische. In: L. Bolk, et alia, Handbueh der vergleichenden 
Anatomie der Wirbeltiere, vol. 4: 345-353. 
HUSSAKOF, L. 

1911. The Permian fishes of North America. Carnegie Institute 
Publ. no. 146: 153-178. 
Jarvik, E. 

1942. On the structure of the snout of crossopterygians and lower 

gnathostomes in general. Zool. Bidrag., 21: 237-675. 
1944. On the dermal bones, sensory canals and pitlines of the skull 
in Eusthenopteron foordi Whiteaves, with some remarks on 
E. save-soderherglii Jarvik. K. Svenska Vetens.-Akad. Handl., 
(3) 21: 1-48. 
1948. On the morphology and taxonomy of the Middle Devonian 
osteolepid fishes of Scotland. K. Svenska Vetens.-Akad. Handl., 

(3) 25: 1-301. 

1950. On some osteolepiform crossopterygians from the Upper Old 
Red Sandstone of Scotland. K. Svenska Vetens.-Akad. Handl., 

(4) 2: 1-35. 

1954. On the visceral skeleton in Eustlienopteron with a discussion of 
the palato-quadrate in fislies. K. Svenska Vetens.-Akad. Handl., 
(4) 5: 1-104. 
1962. Les Porolepiformes et I'origine des urodeles. Colloques Internat. 
du Centre National de la Recherche Scientifique, Paris, no. 
104: 87-101. 
Jordan, D. S. 

1923. A classification of fishes. Stanford Univ. Publ. Univ. Biol. Sci., 
3 (2): 77-243. 
M 'Coy, F. 

1855. Systematic description of the British Palaeozoic fossils. In: 
Sedgwick and M 'Coy, The British Palaeozoic Rocks and Fossils. 
Cambridge, 661 pp. 



THOMSON : MEGALICHTHYS AND ECTOSTEORHACHIS 309 

MlALL, L. C. 

1884. On a new specimen of Megaliohthyn from the Yorkshire coal 
field. Quart. Jour. Geol. See. London, 40: 347-352. 
Moy-Thomas, J. A. 

1935. Notes on the types of fossil fishes in the Leeds City Museum. 
I and II. Acanthodii, Dipnoi, Crossopterygii and Elasmo- 
branehii. Proc. Leeds Lit. Phil. Soe. (Sci. Sect.), 3: 111-116. 

Neave, S. a. 

1940. Nomenclator Zoologieus. Vol. 3. Zool. Soc. London. 
i^RVIG, T. 

1957. Remarks on the vertebrate fauna of the lower Upper Devonian 
of Escuminac Bay, P.Q., Canada, with special reference to the 
porolepiform crossopterygians. Arkiv. Zool., 10 (6) : 367-426. 
Owen, R. 

1840- Odontography. London, 2 vols., 655 pp. 

1845. 

1853. Notice of a batrachoid fossil in British coal shale. Quart. Jour. 
Geol. Soc. London, 9: 67-70. 

ROMER, A. S. 

1937. The braincase of the Carboniferous crossopterygian Megalich- 
ihys nitidits. Bull. Mus. Comp. Zool., 82 (1): 1-67. 

1941. Notes on the crossopterygian hyomandibular and braincase. 
Jour. Morph., 69 (1): 141-160. 

Smith-Woodvfard, a. S. 

1891. Catalogue of the fossil fishes in the British Museum. Part 2. 
London, 567 pp. 
Thomson, K. S. 

1962. Rhipidistian classification in relation to the origin of the 
tetrapods. Breviora, Mus. Comp. Zool., no. 177: 1-12. 
Traquair, R. H. 

1884. Remarks on the genus Mcgalichthys Agassiz, Avith description 
of a new species. Geol. Mag., (3) 1: 115-121. 
Watson, D. M. S. 

1926. The evolution and origin of the Amphibia. Phil. Trans. Roy. Soc. 
London, (B) 214: 169-257. 
Wellbourne, E. D. 

1900. On the genus Mcgalichthys Agassiz, its history, systematic 
position, and structure. Proc. Yorks. Geol. Soc, 14: 52-71. 
Westoll, T. S. 

1936. On the structures of the dermal ethmoid shield of Ostcolepis. 
Geol. Mag., 73: 157-170. 

1937. On a specimen of Eusthenopfrron from the Old Red Sandstone 
of Scotland. Geol. Mag., 74: 507-524. 

1943. The origin of the tetrapods. Biol. Rev., 18: 78-98. 
Whitley, G. 

1940. The Nomenclator Zoologieus and some new fish names. Austr. 
Nat., 10: 241-243. 



310 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Young, J. 

1868. On the so-called labyrinthodont, Parahatrachus (Owen). Trans. 
Nat. Hist. Soc. Glasgow, (n.s.) 1: 174-176. 

(Eeceived May 10, 1963) 

ABBREVIATIONS USED IN THE ILLUSTRATIONS 



a.d.f. 


anterior dentary fossa 


a.e.e. 


anterior extension of the endocranium 


ang. 


angular 


al.ps. 


anterior lamina of para sphenoid 


ant.m.v. 


anterior margin of vomer 


a.p.r. 


anterior palatal recess 


a.pr. 


anterior postrostral 


art. 


articular 


a.t. 


anterior tectal 


Cl-3 


coronoids 


ch. 


choana 


cr.d. 


crista dentalis 


d. 


dentary 


ds. 


dermosphenotic 


d.t. 


dentary tusk 


e.n. 


external naris 


eth.comm. 


ethmoid commissure of lateral line system 


ff>: 


groove in surface of lower jaw 


i.o.l. 


infraorbital lateral line 


ju. 


jugal 


I. 


lachrymal 


l.r. 


lateral rostral 


m.pr. 


median postrostral 


mx. 


maxilla 


n. 


nasal 


n.c. 


nasal cavity 


n.pr? 


possible united nasal and postrostral 


n.r.p. 


na so-rostro-premaxilla 


pa. 


parietal 


p.n. 


postnarial 


po. 


postorbital 


p.op. 


preopercular 


po.s. 


postsplenial 


p.pa. 


postparietal 


p.pr. 


posterior postrostral 


p.pr.n. 


posterior postrostral united with nasal 


pr. 


postrostral 


pr. art. 


prearticular 



THOMSON: MECAI.K II'1'II\S AM) KCTOS'li :()K 1 I A( 1 1 1 

prji. preiiarial 

p.s. parasi)heiioid 

q.j. quadrato-juKal 

r.p.^. iiiediaii ridt^c dC pa lasiiliriioiil 

.1. splenial 

s.diif/. suraiigular 

ff.nili. symphysial iiicntal hone 

.v.". siijiraorbital 

s.d.l. siiiiraorbital lateral liiic 

so.t. supraoibito-tt'ctal 

sq. s(iuaniosal 

st, siipratempoial 

t. tabular 

V. vomer 

vt. vomerine tusk 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 




Plate 1. MegnlicMhys macropomus Copo. MCZ 5143. Lcavemvorth Coal ; 
Lansing, Kansas. Dorsal view showing (U'liiinl lionos of I'tlimoid division 
of skull roof. Al)l)rcviations: na., nasal; pa., parietal; pn., jiostnarial; 
p.pr., posterior postrostral; pr.n., prenarial. 



Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. 131, No. 10 



THE COMPARATIVE ANATOMY OF THE SNOUT IN 
RHIPIDISTIAN FISHES 



By Keith Stewart Thomson 



CAMBRIDGE, MASS., U.S.A. 

printed for the museum 
August 12, 1964 



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Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. 131, No. 10 



THE COMPARATIVE ANATOMY OF THE SNOUT IN 
RHIPIDISTIAN FISHES 

By Keith Stewart Thomson 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

AuGu.sT, 1964 



Bull. .Mils. ('(iin|i. Z(M)1., Ihirvnnl I'niv., 131 ( 10) :313-357, Aiignst, 1904 

No. 10 — The romparativc anatomy of the suoul in rkipidistian 

fishes 

By Keith Stewart Thomson^ 



INTRODUCTION 

Due mainly to the work of Goodrich and Gregory it is now 
almost universally accepted that the Rhipidistia (fossil fishes 
of the order Crossopterygii, in the system of Romer, 1955) are 
the closest ancestors of the tctrapods. In general it has been 
assumed that the first tetrapods, the Amphibia, were of mono- 
phyletic origin, but certain theories of a diphyletic origin have 
been proposed. It has been argued that, of the living Amphibia, 
the Urodela and Anura represent two distinct lineages. Also, 
while the fossil history of the Recent Amphibia is very incom- 
plete, it has been noted that the two major groups of Palaeozoic 
amphibians, the Apsidospondyli and the Lepospondyli, have yet 
to be show7i to have a common ancestor. Both Save-Soderbergh 
and Holmgren proposed a diphyletic theory whereby the Dipnoi 
were stated to be the ancestors of the Urodela and the Rhipidistia 
the ancestors of the Anura. This theory is not now generally 
accepted. A second di]ihyletic theory is that of Jarvik (1942) 
who, while rejecting the Dipnoi as possible ancestors, proposed 
that the Urodela and Anura arose from separate stocks of Rhi- 
pidistia. It is with this theory that the present investigation is 
concerned. 

From a study of the snout anatomy of the Rhipidistia and a 
review of the anatomy of the snout in other gnathostomes, Jarvik 
(1942) concluded that the Rhipidistia comprise two separate 
stocks — the "Porolepiformes" (families Porolepidae and Holop- 
tychidae) and the "Osteolepiformes" (family Osteolepidae and 
Rhizodontidae). Jarvik studied the Lower Devonian genus 
Porolepis as his type of the "Porolepiformes" and the Upper 
Devonian rhizodontid genus Eusthenopicron as his type of the 
"Osteolepiformes." He gives a detailed account of the snout 
anatomy of these two forms and of the differences between them. 
He considers that the differences he observed indicate a basic 
split in the Rhipidistia. Further studies (1962) have elaborated 
this theory. 

Jarvik claims that the two groups of Rhipidistia gave rise 

1 Present address : Departnieut of Z(iolo.u:.v, I'nivcrsity College London. 



316 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

independently to tetrapod vertebrates — the " Porolepif ormes " 
to the TJrodela, and the " Osteolepif ormes " to the Anura and 
probably to all other vertebrates. Jarvik's evidence for this is 
that from an extensive review of the snout anatomy in certain 
Amphibia he concluded not only that the Urodela were funda- 
mentally different from the Anura, but that the diagnostic fea- 
tures of distinction between the two ''types" of snout anatomy 
could be identified in the two "stocks" of Rhipidistia also. Thus 
he believes that the supposedly "characteristic" natures of the 
snouts of "porolepiform" and " osteolepif orm " rhipidistians 
have survived essentially unchanged in the Recent amphibians. 

In general there has been hesitation in accepting Jarvik's con- 
clusions because, in the first place, it is only the snout region that 
has been studied in detail and examination of the entire anatomy 
might yield different results, and, in the second place, because 
the comparisons made were rather limited in scope. Of the 
Amphibia only Salamandra and Rana were discussed in detail, 
and, even more important, of the Rhipidistia only Porolepis and 
Eusthenopteron were available for study. 

The present paper is concerned primarily with the evidence 
for a basic distinction between the "Porolepiformes" and the 
" Osteolepif ormes, " for all subsequent phylogenetic hypothesis 
must rest upon the validity of this proposed dichotomy. 

For many Rhipidistia there is little material preserved in a 
fashion suitable for detailed palaeo-anatomical studies, but of 
the osteolepid genus Ectosteorhachis (previously confused with 
Megalichthys, see Thomson, 1964) from the Lower Permian of 
North America, much well preserved material exists. I have 
used this material to prepare a detailed account of the snout 
anatomy of Ectosteorhachis. The knowledge gained from this 
study, together with other information concerning different gen- 
era of Rhipidistia (0rvig, 1957; Vorobjeva, 1959, 1960a, 1960b; 
Kulczycki, I960; Thomson, 1962; Jarvik, 1962) which has be- 
come available since the date of Jarvik's original work, enables 
us to view the anatomy of the Rhipidistia from a broad and more 
truly comparative basis. The last section of this paper is a criti- 
cal re-evaluation of Jarvik's theory in the light of this com- 
parative study. Since the basis for Jarvik's theory was evidence 
from the nasal/ethmoid anatomy of the Rhipidistia, the present 
investigation is naturally centered in this region. 

This study forms part of the work presented to the Depart- 
ment of Biology at Harvard University in fulfillment of the 



TIIOIMSON : KlIll'IDlSTIAN SNOUT 317 

requirements for the degree of Doctor of Philosophy. During 
my studies I have been greatly helped and encouraged at all 
times by mj^ advisor, Professor A. S. Romer, and I must thank 
him also for the use of the collections and facilities of the 
Museum of Comparative Zoology. The staffs of the Palaeontology 
Preparation Laboratory and the Library at the Museum of 
Comparative Zoology have helped me with many kindnesses 
and courtesies. This study was undertaken while I was a recip- 
ient of North Atlantic Treaty Organization Science Studentship 
3/60/955 administered by PI. M. Department of Scientific and 
Industrial Research, London, during the years 1960 to 1963, and 
the Jeffries Wyman Scholarship at Harvard University during 
1960/1961. 

MATERIALS AND METHODS 

The material of Ectosteorhachis used in this study comes from 
the collection of the Museum of Comparative Zoology at Harvard 
University. It has been collected in the Lower Permian "red- 
beds" of North Central Texas; several specimens of this col- 
lection were used in a previous study of Ectosteorhachis 
{"Megalichthys") made by Romer (1987). 

The major part of the study has been made from a particu- 
larly complete skull (MCZ 8662) from the Belle Plains Forma- 
tion, "Wichita Group, Archer County, Texas, that was sectioned 
transversely at one-quarter millimetre intervals by the celloidin 
peel method. Experiments were made to stain the sections : a 
saturated solution of Alizarin Red S in 95 per cent ethyl alcohol 
used after the section had been oxidised by immersion in 0.25 
per cent potassium permanganate gave the best results, but in 
general it was found that direct examination of the unstained 
section under a microscope was the best method of studying 
the sections. Wax-plate reconstructions were made of the snout 
region. 

I have also used the series of sections made in the horizontal 
and sagittal planes previously prepared by Dr. Romer (cf. 
Romer, 1937). 

Of other Osteolepidae, and of the Rhizodontidae, Porolepidae 
and the Holoptychidae, I have studied the collections of the 
Museum of Comparative Zoology at Harvard University, the 
American Museum of Natural History, the Chicago Natural 
History Museum, the British Museum (Natural History) and the 
Royal Swedish Natural History Museum. 



318 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

ECTOSTEORHACHIS 

Skeleton of the Snout Region 

Dermal hones of the skull roof and palate. A full description 
of the dermal bones of the ethmoid region of the skull of Ect- 
osteorhacMs has already been given (Thomson, 1964). As shown 
in Figure 3, the dermal skull roof consists, in the ethmoid region, 
of a pair of parietal bones which bear the supraorbital lateral 
line canals forwards and mesially from the dermosphenotics ; a 
single median postrostral bone ; paired anterior postrostral 
bones; a compound naso-rostro-premaxilla (termed "premax- 
illa" throughout this paper) ; a lachrymal bone; prenarial and 
postnarial bones ; and a .series of four separate nasal bones which 
bear the supraorbital lateral lines, on each side, from the parietals 
forward to the ethmoid commissure with the infraorbital lateral 
liue. The infraorbital lateral line canal, on each side, runs in a 
shallow loop, ventral to the naris and the pre- and postnarial 
bones, in its passage between the lachrymal and the premaxilla. 

On the palate the vomers are roughly triangular in shape 
(Fig. 4) and the tooth-bearing ridge of the parasphenoid ends 
anteriorly at the level of the postnasal wall. The vomers form 
the posterior margin of an "anterior palatal recess" — a shal- 
low recess formed between the anterior margin of the ethmoid 
endocranium and the premaxillae. The expanded bases of a pair 
of premaxillary "tusks," in the midline, separate the recess into 
two parts. The functional significance of the anterior palatal 
recesses will be discussed later. 

External features of the eyulocranium. The endocranium of 
Ectosteorhaehis has already been described in some detail by 
Romer (1937, pp. 18-22). My purpose here is therefore to add 
to Romer 's account those details of structure not shown in his 
material, which was incomplete in the nasal region. 

Figures 1 and 2 show the overall configuration of the endo- 
cranium. The nasal capsules of Ectosteorhaehis are complete 
dorsally and laterally except for the foramina for the exit of 
various canals for nerves from the nasal cavity (e.g. Fig. 1, 
f.ap.). The anterior wall and the posterior wall of the capsule 
are pierced by canals for various nerves and vessels (discussed 
in the next section) ; the lateral wall is broken only by the 
fenestra endonarina. The median wall of the capsule is formed 
l)y the solid internasal wall ; this is pierced by the canals carry- 
ing the olfactory tract and also by several vascular and nervous 
pathways. 



THOMSON : HIIIPIDISTIAN SNOUT 



319 



The roof and very thin side walls of the nasal capsule are, for 
the most part, fused with the overlying dermal bones. On the 
medial face of the lateral Avail of the capsule, immediately pos- 
terior to the fenestra eiidoiiarina, there is a small elliptically- 
shaped ridge of endocranial bone projecting into the nasal cavity. 
This ridge, which I have termed the crista lateralis (Figs. 5, 9, 
c.L), bears on its median face a groove (Figs. 5, 9, gr.c.l.) which, 
from its relation to the external narial aperture, may have par- 
tially enclosed the tube for the external naris. 

The posterior wall of the capsule, in addition to being pierced 
by the canals which in all probability carried the ophthalmicus 
superficialis seventh and profundus fifth nerves mentioned by 
Romer (1937), has a large opening in the ventrolateral corner 
(Figs. 3, 4, 5, 10 D and E, p.v.f.) — the posteroventral fenestra 
— the significance of which is rather enigmatical. Jarvik con- 
sidered a similar fenestra in Eusthenopteron to represent a 




Figure 1. Ectosteorhachis. Ethmoid eudocranium in dorsal view. 



320 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



modified posterior external naris which might possibly be con- 
nected by means of a duct (the forerunner of the tetrapod naso- 
lachrymal duct) with the orbital opening. It is not impossible 
that this fenestra served to permit the passage to and from 
the nasal cavity of large blood vessels. 

The ventral wall of the nasal capsule is not preserved in any 
of the material studied by Dr. Romer or myself. In view of 
the otherwise excellent preservation of the specimens it seems 
most likely that the solum nasi was not ossified but was present 
in the living animal only in a cartilaginous form. The position 
of the choana may easily be inferred from the relative positions 
of the vomer, palato-quadrate and the dermal bones of the cheek. 

The pars autopalatina of the palato-quadrate was inserted into 
the notch formed between the median part of the postnasal wall 
and the endocranium (Fig. 2, 7i. pq.). This notch is not lined 
with periosteal bone like the rest of the nasal region and it is 
possible that the junction between the endocranium and the 
palato-quadrate in this region was not a free articulation. 

pm.t. 




Figure 2. Ectostcorhachis. Ethmoid endocrauium in ventral view. 



THOMSON: RIIIPIDISTIAN SNOUT 321 

The endocranial and associated cavities. In P^'igures 3 and 4, 
which show the general configuration of the endocranial cavities, 
the details of the hypophj-sial region have been restored, without 
modification, after the account of Romer (1937, figs. 9, 10). 

The cranial cavity in tlie ethmoid division of the skull of 
Ectosteorhachis consists of spaces containing the hypophysial and 
])ineal regions and the olfactory tracts. Since there is no part 
of the forel)rain corresponding to the olfactory bulbs, it is as- 
sumed that the olfactory bulbs are represented by swellings 
in the canals for the olfactory tracts, as is the case in the 
Dipnoi (cf. Pinkus, 1895). There is no continuation of the 
cranial cavity anterior to the point of separation of the two 
olfactory tracts; the internasal wall contains no large cavities. 

Immediately anterior to the level of the separation of the 
olfactory tracts there arises, from the ventral surface of the 
canal for each tract, a set of fine canals (Fig. 4, cc.mea., c.ana.) 
that I have interpreted, judging from their position and dis- 
tribution, as having carried vessels probably connected with 
the internal carotid artery. There are two sets of canals. A 
series of smaller ramifying canals pass forwards medial and 
ventral to the olfactory tract canal and terminate in the highly 
cancellous internasal wall (Fig. 4, cc. mea.) . A single larger 
canal immediately separates from the smaller canals and runs 
forwards (Fig. 4, c.ana.) ventral to the olfactory tract canal; 
at a point just posterior to the nasal cavity it recombines with 
this canal. 

Another set of canals arises from the dorsal surface of the 
canal for the olfactory tract just posterior to the nasal capsule ; 
these canals (Fig. 3, c.ni.cut.va., c.l.cut.va.) seem also to have 
contained vascular elements and extend in three directions in 
the endocranium. (1) An anterior canal has a short connection 
back to the canal for the olfactory tract and a stout branch curv- 
ing forwards over the nasal sac. It has a short cross-connection 
to the canal for the ophthalmicus superficialis seventh nerve 
(see below), as it passes through and above the postna.sal wall. 
According to Romer (1937) there is a complete fusion of the 
two canals here and thej' enter the nasal cavity together. My 
material indicates, however, that the canals are distinct from 
each other and from the nasal cavity. The anterior canal disap- 
pears in the anterior part of the endocranium medial to the 
nasal capsule. (2) A median canal (Fig. 3, c.m.cut.va.) passes 
anteromedially and opens onto the dorsal surface of the endo- 
cranium below the median postrustral bone of the dermal skull 



322 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



roof (Fig. 3, m.pr.). (3) A lateral canal terminates in the 
lateral part of the endocranium behind the nasal cavity (Fig. 
3, c.l.cut.va.). 

Komer (1937, p. 32) has already noted that the posterior wall 
of the nasal capsule is pierced by two canals which seem to 
have carried the ophthalmicus superficialis VII and profundus 




Figure 3. Ectosteorliachis. Endoeranial cavities and the dermal bones of 
the skull roof. Dorsal view. 



V cranial nerves, the canal for the former lying dorsolateral of 
the canal for the latter. The canal for the profundus V (Fig. 3, 
c.pr.V) is a short simple tube through the postnasal wall; there 
is a slight connection within the postnasal wall with the canal 
for the ophthalmicus superficialis VII. The latter canal is en- 
tirely separate from the nasal cavity, within the postnasal wall. 
In addition to the connection with the canal for the profundus 

V and the anterior vascular canal noted above, there is given off 
from the canal for the ophthalmicus superficialis VTT the first of 



THOMSON: KHIPIDISTIAN SNOUT 



323 



a series of dorsal bi-aiu-hes which pass out of ihc ciKlocraiiiuin 
(Fig. 1, ff.ros.) and obviously contained branches of the nerve 
supplying the sense organs of the supraorbital lateral line canal. 
The canal for the ophthalmicus superficialis VII curves forwards 
through the roof of the nasal capsule and emerges from the 
endocranium at about the level of the anterior na.sal wall and 
thence continues in the space between the endocranium and the 
dermal bones. 

The anterior wall of th(> nasal (•ai)su]e is pierced by a series 
of fine canals (Figs. 3, 4, cc.aa.) which communicate with the 
palatal recess and the medial surface of the premaxilla. 

A fine canal (Fig. 3, c.lat.) passes through the posterolateral 
corner of the nasal capsule from the medial surface of the 
lachrymal bone without entering the nasal cavity. 

The medial wall of the capsule is pierced by two nerve canals 
in addition to the canal for the olfactory tract. The more pos- 
terior of the two canals (Fig. 3, c.r.ext.) leaves the nasal cavity 




Figure 4. Ectosteorhachis. Endocranial cavities aud dermal bones of 
palate. Ventral view. 



324 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



just anterior to the canal for the olfactory tract and passes 
dorsally, anteriorly and medially to open at the foramen apicale 
on the dorsal surface of the endocranium (Fig. 1, f.ap.). Romer 
considered that the foramen apicale was the opening of the canal 
for the ophthalmicus superficialis VII, but the situation of this 
canal seems to indicate that it contained the ramus exterior of 
the profundus V nerve (discussion below). The more anterior 
canal piercing the medial nasal wall leaves the nasal cavity at 
the dorsal part of the anteromedial recess (discussed below). 
This canal (Fig. 3, c.r.r.) passes anteriorly to emerge on the 
anterior margin of the endocranium dorsal to the anterior 
palatal recess ; it seems to have carried an anterior branch of the 
profundus V system. 

Also opening through the medial wall of the capsule is a set 
of branching canals (Fig. 4, c.mev.) which ramify within the 
internasal septum. This canal system probably contained a set 
of veins draining into the nasal cavity. 




Figure 5. Ectosteorhachis. Nasal cavity. A. Left cavity in anterior view. 
B. Left cavity in posterior view. Graphical reconstructions from the 
sectioned specimen. 



The nasal cavity itself is roughly elliptical in shape with 
the long axis of the ellipse lying at an angle of about 45° to the 
anteroposterior axis of the head. The inner surface of the nasal 
capsule is not ornamented and the only modifications of the 
otherwise smooth contour of its surface are caused by the pos- 
terior median recess (Fig. 5, p.rcc.) into which the olfactory 
tract entered, and an anterior median recess (Fig. 5, a.m.r.) 
(termed the ventromedial recess by Romer, and already discussed 
by that author). The crista lateralis broadly separates a choanal 



THOMSON: KI III'IDISTIAN SNOUT 32') 

recess from the I'est of the nasal ehaiiiher. The groove on the 
median surface of the crista lateralis may have borne a short 
narial tube connecting the naris and the nasal chamber (Fig. 3, 

Certain of the dermal bones contain cavities which are clearly 
related to the canals for nerves and vessels which pass through 
the endocranium. 

Each vomer is pierced by a medial and a lateral canal (Fig. 4, 
m.c.v., l.c.v.) which are occasionally branched. There are no 
cross-connections between the canals, but the lateral canal, on 
one side of the specimen sectioned, has a dorsal branch which 
emerges on the dorsal face of the vomer underneath the nasal 
cavity. Since the solum nasi is not preserved it is not possible 
to detect whether or not this branch actually connected with the 
nasal cavity. 

Neither vomerine canal can be traced posteriorly ; it is as- 
sumed that the medial canal would have been continued medial 
to the palato-quadrate complex, between it and the parasphenoid 
bone, and it probably contained the palatine ramus of the 
seventh cranial nerve. The lateral canal must have been con- 
tinued backwards lateral to the choana and between the palato- 
quadrate and the lachrymal ; this canal probably contained the 
maxillary ramus of the fifth cranial nerve. 

The nasal, parietal, premaxillary and lachrymal bones of the 
skull roof enclose a large canal (Fig. 8, c.l.l.) w'hich, from its 
pathway over the skull roof, its relation to the course of the 
canal for the ophthalmicus superficialis VII nerve, and the dis- 
position of its tine branches relative to the centres and modes of 
radiation of the dermal l)ones, obviously contained the supra- 
orbital and infraorbital divisions of the lateral line system. The 
canal for the infraorbital lateral line, as it passes through the pre- 
maxillae and lachrymal bones, is surrounded by several smaller 
canals which branch and ramify with the lateral line canal and 
with each other. These smaller canals must surely have carried 
vessels and nerves associated with the lateral line organs, includ- 
ing, in all probability, the buccalis lateralis branch of the seventh 
cranial nerve. The only connections between the canal for the 
infraorbital lateral line and the medial surface of tiie dermal 
bones occur once in the lachrymal bone and once in the pre- 
maxilla. 



326 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



The Nerves of the Ethmoid Region' 

The fifth cranial nerve. The ramus profundus of the fifth 
cranial nerve leaves the cranial cavity through the space between 
the two divisions of the endocranium (see Romer, 1937). Of the 
further anterior course of the nerve nothing may be seen until 
it re-enters the endocranium through the postnasal wall (Fig. 3, 
c.pr.Y). Within the nasal cavity the nerve probably divided 
into two main branches, a ramus medialis narium and a ramus 
lateralis narium (Fig. 6, r.m.n., r. In.), as is the case in the 
Dipnoi and Amphibia. However, while the presence of a branch- 
ing ramus medialis narium is shown by various canals through 




Figure 6. Ectosteorhachis. Reconstruction of the nervous system of the 
snout. Left in ventral view. Right in dorsal view. Portions of nerve 
course represented by an endocranial canal drawn in solid black, recon- 
struction in white. 



1 Unless otherwise stated, tlio teriiiinolo<;y used in this section follows the 
system used by Jarvik (1942). 



THOMSON: KI 1 U'lDISTIAN SNOUT 



327 



llu" inedial wall of the nasal capsule, similar direct evidence of 
the path of the ramus lateralis narium is lacking. 

The canal which opeii« out of the nasal cavity just anterior to 
the opening for the olfactory tract (Fig. 3, c.r.ext.) probably 
contained the "ramus exterior" of the profundus V; tliis nerve 
j)assed dorsally and medially to leave the endocranium at the 
foramen apicale. Anterior to this a second branch of the pro- 
fundus V leaves the nasal cavity through the canal opening into 
the anterior palatal recess (Fig. 3, c.r.r.). I have termed this 
branch the "ramus rostralis" of the ramus medialis narium (Fig. 
6, r.r.). The canal carrying this nerve has a slight connection 
with that carrying the ophthalmicus superficialis VII nerve, but 
anastomosis between these two nerves in this position seems un- 
likely and the connecting canal probably contained a small vessel. 
A third set of branches of the ramus medialis narium, which I 
have termed the "anterior rami" (Fig. 6, a.r.), pass through the 
anterior nasal wall. 




Figure 7. Ectosieorhachis. RcconstriR'tioii of vascular system. Left in 
ventral view, right in dorsal view. Portions of vascular system represented 
by endocranial canals drawn in solid black, reconstruction in white. 



328 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

The ramus maxillaris of the fifth cranial nerve seems most 
likely to have been contained in the canal passing through the 
lateral edge of the vomer (Fig.s. 4, 8, l.c.v.). This nerve (Fig. 
6, r. max.) thus corresponds to the "r.vot." of Jarvik (1942, 
fig. 61) and the branch of the maxillary fifth which in EustJienop- 
teron may have formed a post-choanal anastomosis with the 
ramus palatinus VII. Whether such an anastomosis existed in 
Ectosteorhachis can only be a matter for conjecture. 

Other branches of the ramus maxillaris must have passed to 
and probably within the dermal bones of the anterior part of 
the cheek. If there was a ramus infraorbitalis it must have en- 
tered the nasal cavity at the problematical posteroventral fen- 
estra or have passed forward entirely outside of the nasal cavity. 

The seventh cranial nerve. The ramus ophthalmicus super- 
ficialis of the seventh nerve enters the endocranium through the 
canal, in the dorsal part of the postnasal wall, described above 
(Fig. 3, c.ros.VII). As it passes through the endocranium in a 
curved path corresponding to, but slightly medial to, the path 
of the supraorbital lateral line canal, the ramus ophthalmicus 
superficialis gives off a series of fine dorsal branches supplying 
the lateral line organs. Anteriorly, after emerging onto the 
surface of the endocranium, the nerve passes forwards and then 
laterally, curving around to the ethmoid commissure of the lat- 
eral line system ; however, in this region of the snout it is ex- 
tremely difficult to trace the finer details of the various nerve 
pathways. 

The ramus palatinus VII seems to have been carried in a canal 
in the medial part of the vomer (Figs. 4, 8, m.cv.). Anterior to 
the vomer the nerve probably passed into the anterior palatal 
recess region ; posterior to the vomer it probably passed between 
the palato-quadrate and parasphenoid bones (Fig. 6, r.pal.). 

Since the infraorbital lateral line is well developed in Ect- 
osteorhachis, the ramus buccalis lateralis VII must also have been 
present. The path of the infraorbital lateral line in the nasal 
region (see Thomson, 1964) curves ventrally below the circum- 
narial bones, and thus in this region the lateral line canal is 
morphologically ventral to the level of the solum nasi. This being 
the case, it is unlikely that the ramus buccalis lateralis would 
have passed within the nasal cavity as it does in the genus 
Eusthenopteron (Jarvik, 1942) ; furthermore, only in two places, 
one within the lachrymal bone and one at the very tip of the 
premaxilla, is there any connection between the canal for the 



THOMSON : RHIPIDISTIAN SNOUT 329 

infraorbital lateral line and the medial face of the bones contain- 
ing it. (Conceivably the anterior of these two connections served 
to pass branches of the ophthalmicus superficialis VII to the 
infraorbital part of the ethmoid commissure.) We have noted 
above that the canal for the lateral line is, in this region, sur- 
rounded by a set of smaller anastomosing canals also contained 
in the body of the dermal bones, and we must conclude that the 
ramus buccalis was most likely to have been carried in one of 
these canals. 

The Vascular System of the Ethmoid Region 

Arterial system. Romer (1937) has already described the 
arrangement of the internal carotid, palatine, and ophthalmic 
arteries in the hypophysial region of Ectosteorhachis; the fur- 
ther anterior courses of the palatine and ophthalmic arteries can- 
not be traced in the fossils. 

After it has entered the cranial cavity the internal carotid 
can only be traced by the paths of those of its branches which 
subsequently leave the cranial cavity. The canals for such 
branches have been described above. A prominent set of branches 
(Fig. 4, cc. mea., c.ana.) appears to have passed out from the 
ventral surface of the canal for the olfactory tract just anterior 
to the separation of the two tracts. A set of three or four median 
ethmoid arteries (Fig. 7, mca.) ramify through the median part of 
the ethmoid endocranium. They pass right up to the tip of the 
endocranium, but their most anterior passage is very difficult to 
follow, since the endocranial bone in this region is extremely 
cancellous; accordingly I have restored them (Fig. 7) only in a 
diagrammatic fashion. A single and rather larger canal branch- 
ing from the endocranial cavity at the same point (Fig. 4, c.ana.) 
also seems to have contained an artery, which I have termed 
the anterior nasal artery. This artery passes forwards beneath 
the olfactory tract right up to the nasal region where its canal 
rejoins that for the olfactory tract and presumably the artery 
enters the nasal cavity thereby. 

The set of canals which branch off from the canal for the 
olfactory tract dorsally, just posterior to the nasal region, seem 
most likely to have contained arterial vessels also. I have termed 
these the cutaneous arteries; there are three main elements, 
anterior, median and lateral. The anterior cutaneous artery 
passes forwards dorsal to the olfactory tract and curves over 



330 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

the nasal region, following approximately the path of the supra- 
orbital lateral line canal (Fig. 7, a.cut.va.). Immediately after 
the separation of this artery from the canal for the olfactory 
tract there is a short connection back to this canal (Fig. 7, olf.c.) 
which may have held a vessel. The series of short connecting 
canals between the canals for the anterior cutaneous artery, the 
ramus ophthalmicus superficialis VII and the profundus V may 
also have carried branches of this anterior artery. The median 
cutaneous artery passes anteromedially towards its fellow of the 
opposite side (in my material the canals did not appear to meet 
as Romer, 1937, had described), and terminates under the pos- 
terior part of the median postrostral bone. The lateral cutaneous 
artery terminates in the lateral endocranium posterior to the 
nasal capsule. 

Venous system. There are fewer canals for the passage of 
veins in the ethmoid region than for arteries. 

A set of branching canals opening into the anterior part of 
the posterior median recess of the nasal cavity (Fig. 4, c.mev.) 
seems to have contained a set of venous vessels draining the 
internasal part of the ethmoid endocranium. The finer branches 
of these "median ethmoid veins" which are not shown in the 
restoration (Fig. 7) seem to terminate in the same general region 
as do those of the median ethmoid arteries. 

The wall of the posterolateral corner of the nasal capsule is 
pierced by a canal which may also have contained a small vein, 
the lateral nasal vein. This does not enter the nasal cavity (Fig. 
3, c.lat.), but passes from the space between the dermal bones 
of the skull roof to the orbital cavity. 

Since the arterial supply to the nasal cavity seems to have 
been well developed, there must have been a substantial venous 
system draining the nasal chamber. This is borne out by the fact 
that the veins draining the internasal wall also pass into the 
nasal chamber. There are two alternative routes by which veins 
may have left the nasal cavity : either they passed alongside the 
profundus nerve in its canal through the postnasal wall, or they 
passed through tlie posteroventral fenestra. There is no way of 
deciding between these alternatives. It may, however, be noted 
that the posterior opening of the canal for the presumed lateral 
nasal vein is in the same general region as the posteroventral 
fenestra, and in the absence of some other acceptable ex]>lanation 
of the function of the posteroventral fenestra, the possibility that 
it served for the passage of vascular elements should not be 
ignored. 



THOMSON: RIIllMDISTIAN SNOUT 331 

As a filial note on the vaseular system it should be noted that 
the canals piercing' the antcrioi- wall of the nasal capsule may 
have contained vessels as well as nerves. 

DISCUSSION 

The Ethmoid Endockanium 

The ethmoid endocraiiiiim has boon described in the folloAving 
i-hipidistian g'onera : Ecfostcorhachis (Komer, 1937, 1941); Eus- 
thenopicron (Bryant, 1919; Stensio, 1922; Holmgren and Sten- 
sio, 1936 ; Sternberg, 1941 ; Jarvik, 1937, 1942, 1954) ; Glypiolepis 
(Jarvik, 1962) ; T'andcrichfhys (Vorobjova, 1960a) ; Flatycepha- 
lichthys (Vorobjova, 1959) ; Porolcpis (Jarvik, 1942; Kulczycki, 
I960); Rhizodopsis (Watson and Day, 1916; Save-Sodorbergh, 
1936). 

More l)riof accounts of those and other genera are also to be 
found in the literature. 

Romer (1937) compared the endocranium of Ectosteorhachis 
with that of those forms then known. To this comparison further 
points may be added, as below. 

Antei'wr palatal recesses.^ In both Ectosteorhachis and Mcga- 
lichthys the anterior palatal recess is divided into two parts by 
posterior expansions of the premaxillae in the midline. In Mega- 
lichtliys (Thomson, 1964), division is aided by a "buttress" 
from the anterior part of the endocranium which fits up against 
the expansions of the premaxillae. In Panderichthys (also an 
osteolepid, see Thomson, 1962), the buttress of the endocranium 
is present but not the premaxillary expansion (see Vorol)jeva, 
1960a, fig. 1). In the rhizodontid Easthcyiopteron the anterior 
palatal recess is undivided. In Porolepis (Porolepidae) and 
Holoptychms (Holoptychidae) the anterior palatal recesses are 
paired and entirely separate from each other. Each recess con- 
sists of a cavum prenasale which corresponds to the anterior 
recess in Osteolepidae and Rhizodontidae, and a cavum inter- 
nasale which extends as a shallow depression under the ventral 
surface of the endocranium (Jarvik, 1942). The two cava inter- 
nasalia are separated by the anterior part of the parasjjhenoid ; 
the cava prenasalia are separated by a ridge of the oiulocranium 
which may correspond to the "buttress" found in some Osteo- 
lepidae. 

lAlso described l).v the terms "apieal iiits." "anterior palatal fenestrae." 



332 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Jarvik (1942) considered that these anterior palatal recesses 
in Rhipidistia contained glandular structures homologous with 
the various intermaxillary glands found in Recent Amphibia. It 
had already been suggested, however, that these recesses served 
for the reception of large "tusks" of the lower jaws when the 
jaws were occluded (Holmgren and Stensio, 1936; Romer, 1937). 
Recent work by Kulczycki (1960), Thomson (1962), and Jarvik 
(1962) has confirmed this view. The characteristic shape of the 
recesses in the Porolepidae and Holoptychidae reflects merely 
the nature of the teeth at the tips of the lower jaws which, in 
these families (0rvig, 1957; Jarvik, 1962), take the form of a 
pair of tooth whorls. 

Pars ethmoidalis cranialis. Jarvik (1942) stated that in 
Porolepis and typically only in the Porolepidae and Holoptychi- 
dae, the cranial cavity in the ethmoid endocranium is continued 
anteriorly, beyond the point of separation of the canals for the 
two olfactory tracts, as a large space — the ' ' pars ethmoidalis 
cranialis." This feature, he stated, was not present in the 
Osteolepidae or Rhizodontidae. 

The inference in Jarvik 's work (cf. Jarvik, 1942, fig. 45 A) 
is that the pars ethmoidalis cranialis contained the hemispheres 
of the forebrain which were situated anterior to the point of 
origin of the olfactory tracts. Jarvik thus supposed that the 
brain of Porolepis corresponded in its morphology to that of an 
urodele such as Salamandra (cf. Francis, 1934, pi. 9, figs. 51, 52), 
as opposed to that of other tetrapods and of Eusthenopteron 
which lack the pars ethmoidalis cranialis and in which the 
olfactory tracts are given off from the very anterior tip of the 
forebrain. 

A review of the evidence, however, shows that the pars eth- 
moidalis cranialis does not occur in any consistent manner in the 
Rhipidistia. Kulczycki (1960) reported that it was absent in the 
material of Porolepis he studied^ and Vorobjeva (1960a) stated 
that this cavity was present both in the osteolepid genus Pan- 
derichthys and the rhizodontid genus Platycephalichthys (see 
Thomson, 1962). When one further bears in mind that the cavity 
in the endocranium does not necessarily reflect the exact con- 
figuration of the brain contained therein, Ave must conclude that 
it is far from certain that a structure as inconsistent as the pars 
ethmoidalis cranialis contained any part of the cerebral anatomy. 



iSome of Kulczycki's oonolnsions must be trcjitert with roscrvatinn, siiico liis 
material consisted only of natural casts. 



THOMSON: KIIIIMDISTIAN SNOl^T 333 

The nasal caj)sules and nasal cavity. The nasal capsule has 
been described in detail only in Eusthenopteron and Porolepis 
(Jarvik, 1942; cf. Kulczycki, 1960). Jarvik concluded from 
his studies that the nasal cavity in Porolepis was fundamentally 
different from that of Eustlunopicron; in the following discus- 
sion I have compared Ectosteorhachis with both of these genera 
to determine whether or not this distinction may be maintained 
in the light of a wider comparison. 

The nasal capsule aiid nasal cavity in Eusthenopteron (Jarvik, 
1942, pp. 464-467) have a complicated configuration. The medial 
wall of the capsule, as in Ectosteorhachis, bears two prominent 
recesses, an anterior one — termed by Jarvik the ventromedial 
recess — which is homologous with the anteromedial recess in 
Ectosteorhachis, and a posterior recess into which, as in Ect- 
osteorhachis, the olfactory tract enters. 

The prenasal wall bears two horizontal ridges which were con- 
sidered by Jarvik (1942, p. 443) to divide the anterior part of 
the nasal chamber into various recesses. A lateral horizontal 
ridge runs from the middle of the prenasal wall onto the lateral 
nasal wall; a smaller and more medial "crista intermedia" runs 
to the anterior corner of the medial wall of the cavity. Neither 
of these ridges is represented in Ectosteorhachis. 

The lateral wall of the nasal capsule of Eusthenopteron bears 
a thick ledge anterior and ventral to the external narial aperture 
and projecting as a flange into the nasal cavity. This large 
structure is termed by Jarvik the "processus intermedins"; its 
anterior part connects with the lateral horizontal ridge of the 
prenasal wall. A process from the lateral rostral dermal bone 
projects onto the processus intermedins and into the nasal cavity 
as a slip of bone — the processus derminterniedius. These two 
processes do not have any direct equivalents in E ctosteorhachis ; 
the possible homology of the processus intermedius with the 
crista lateralis of Ectosteorhachis is discussed below. 

In Porolepis (Jarvik, 1942, pp. 367-372, esp. figs. 40, 42 ; Kul- 
czycki 1960, pp. 74-75, 86-88, fig. 3) there are three main ridges 
on the inner surface of the nasal capsule, all on the lateral wall. 
Again, whether these ridges actually reflect any functional divi- 
sion of the nasal sac is uncertain. The most prominent ridge 
runs from the anterior external naris to the communal opening 
for the posterior external naris and the choana. It separates 
the narial openings from the choanal opening, and, being a quite 
high ridge, has been supposed by Jarvik (1942, p. 402) to have 



334 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

divided the lateral part of the nasal sac into two recesses, the 
more ventral of which he homologises with Jacobson's organ of 
urodeles. Jarvik terms this ridge, in accordance with the sup- 
posed relation with the Urodela, the crista rostro-caudalis. Kul- 
czycki (1960), however, believes that the ventral recess so 
delimited is merely a chamber containing the choaua and he 
terms the ridge "crista subnarina" to avoid hypothetical con- 
siderations of phylogeny. 

The two other ridges on the lateral nasal wall of Porolepis are 
the crista orbito-rostralis which runs from the endochoanal notch 
to the anteroventral margin of the anterior external naris, and a 
thickening of the ventral rim of the fenestra endonarina anterior 
which Kulczycki, supposing it to be homologous with the similar 
structure in Eusthenopteron, terms the process intermedins. 

The crista orbito-rostralis is not present as such in either 
Ectosteorhachis or Eusthenopteron, but it is interesting to reflect 
upon the question of the relationship of the crista subnarina 
(crista rostro-caudalis) of Porolepis to the crista lateralis of 
Ectosteorhachis. Both structures are situated anterior to the 
(anterior) external naris and pass backwards dorsally to the 
choana, separating the choanal recess from the main nasal cham- 
ber : they seem quite likely to be homologous structures/ 

The crista lateralis is lacking in Eusthenopteron, but in this 
genus the processus intermedins (and dermintermedius) has 
taken over the function of separating the choana and external 
naris. We have already noted, above, a possible homologue of 
the processus intermedins in the thickening of the ventral mar- 
gin of the anterior naris of Porolepis, and it is possible to set up 
the following scheme by which the various characteristic ar- 
rangements of the nasal cavity in Porolepis, Eiistlienopteron and 
Ectosteorhachis may be related one to another. 

It seems likely that the ancestral form linking the early poro- 
lepid fishes to the later Devonian Osteolepidae and Rhizodontidae 
was a primitive osteolepid with the external naris situated fairly 
far forward; there may even still have been two external nares, 
as has been reported for PawcZeric^i/iiy.s (Vorobjeva, 1960a). The 
ventral rim of the narial aperture (s) was probably enlarged 
as a thick ridge extending backwards to separate the naris from 



1 If .Tarvik is correct in believing tliat tlie posteroventral fenestra of 
Eusthenopteron (and Ectosteorhachis) corresponds to tlie posterior external 
naris, tlie crista lateralis would have the same relations with the anterior naris, 
choana, and posterior naris as the crista subnarina in Porolepis. 



THOMSON : KIIIPIDISTIAN SNOUT 335 

tlie elioanal rrccss. This ri(l<>-(' would correspond to the crista 
siibnariiia (crista rostro-caudalis) of Porolepis and also to a 
process intermedius. In the Devonian Osteolepidae the more 
anterior part of the ridge was probably developed into a processus 
intermedins and this may even have been overlain by a processus 
dermintermedius from the lateral rostral bone. In the later 
Osteolepidae the more posterior part of the subnarinal ridge 
developed as the crista lateralis ; this change is probably related 
to a nugration of the narial aperture backvrards. There is no 
dermal process comparable to the processus dermintermedius, and 
indeed, in EctosicorhachiH, the part of the lateral nasal wall 
hearing the crista lateralis is overlain by the postnarial bone 
(= tectal of Osteolepis, see Thomson, 1964) rather than by that 
part of the prenarial bone which corresponds to the lateral rostral 
bone. 

The Rhizodontidae seem to have developed from the Osteolepi- 
dae. In the rhizodontids the naris has retained its relation to the 
lateral rostral bone, the processus intermedius is well developed, 
and the posterior part of the subnarinal ridge is lost. The proces- 
sus dermintermedius is well developed and may extend onto the 
prenasal wall of the nasal capsule (Jarvik, 1942). We may con- 
clude that the ethmoid region of the endocranium is apparently 
constructed according to a single general pattern in Porolepis, 
Eusthenopteron and Ectosteorhachis. Furthermore, the osteo- 
lepid Ectosteorhachis is observed to differ from the rhizodontid 
Eusthenopteron no le.ss greatly than either of these genera differs 
from the porolepid Porolepis. 

The Nervous System of the Snout 

Details of the presumed course of the various nerves of the 
snout region of Rhipidistia have been given for the following 
genera only: Porolepis (Jarvik, 1942; Kulczycki,^ 1960); Eus- 
thenopteron (Jarvik, 1937, 1942) ; Ectosteorhachis (Romer, 
1937). Details of the foramina for the profundus V and ophthal- 
micus superficialis VII nerves of Osteolepis and Rhizodopsis are 
given by Watson (1926) and Save-Soderbergh (1936), respec- 
tively. 

The fifth cranial nerve: ramus profundus. In Ectosteorhachis, 
Meejalichthys, Osteolepis, Rhizoelopsis, and most species and 
specimens of Eusthenopteron, the profundus V enters the nasal 

iQiily the better based of Kulczycki's conclusions are considered here. 



336 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

capsule by means of a single foramen in the postnasal wall. In 
Porolepis, according to Jarvik (1942), the profundus branches 
within the orbital region so that two or more rami enter the nasal 
capsule through separate foramina in the postnasal wall. Ac- 
cording to Kulczycki (1960), the profundus in Porolepis 
branched within the postnasal wall itself ; this is reported to be 
the case also in some specimens, at least, of Eusthenodon {Eus- 
thenopteron) wenjucovi (Jarvik, 1937). It must be presumed 
that in all genera of Rhipidistia the profundus branched either 
inside or outside the nasal cavity to innervate both the mesial and 
lateral part of the na.sal cavity, but that the actual site of the 
branching is somewhat variable. 

There were most probably two main branches of the profundus 
within the nasal cavity — the ramus medialis narium and the 
ramus lateralis narium. In all cases the ramus medialis narium 
is the better developed, innervating, in addition to the nasal ap- 
paratus, the septum nasi and the anteromedial parts of the snout. 

In Eusthenopteron and Ecfosteorhachis the only branch of 
the profundus V to pass out through the dorsal surface of the 
endocranium is the ramus exterior. In Porolepis, according to 
Jarvik (1942), the profundus V leaves the nasal cavity through 
several fine canals which pierce the dorsal wall of the nasal 
capsule. One of the canals he described (1942, fig. 43, c.cut.va.) 
is homologous with the ramus exterior but, according to Kulczy- 
cki (1960), the remainder of these fine canals actually belong to 
the superficial ophthalmic branch of the seventh cranial nerve 
and do not arise from the profundus V which is very similar to 
that of other Rhipidistia. 

AVe have seen that the ramus medialis narium in Ecfosteo- 
rhachis has a number of medial and anterior branches and these 
are comparable to the branches of this nerve in Ensihenopteron 
(cf. Jarvik, 1942, fig. 61). In Jarvik 's restoration (1942, p. 376) 
the ramus medialis narium of Porolepis left the nasal cavity only 
by means of the dorsal branches mentioned above, but Kulczycki 's 
restoration (1960, fig. 5) includes one anteroventral canal open- 
ing into the anterior palatal recess of Porolepis which seems to 
correspond to the naso-basal canal (carrying a terminal branch 
of the ramus medialis narium through the prenasal wall) in 
Eusthenopteron and Ectosteorhachis (Jarvik, 1942, fig. 60, cvn-b; 
cf. this paper Fig. 3, cc.aa.). 

As restored by Jarvik, the ramus lateralis narium in Porolepis 
has branches which leave the nasal capsule through the lateral 



THOMSON : HIIIPIDISTIAN SNOUT 



337 



nasal wall (Jarvik, 1942, fig. 42A, ec.pr.l.) ; comparable ele- 
ments are lacking in Eusthcnopteron and Ectostcorhachis. Jarvik 
also described in Porolcpis a third branch of the profundus 
system which enters the ventrolateral part of the postnasal wall 
through the "orbitorostral i)assage" (1942, fig. 42 B, c.cr.). 
After passing along the ventral surface of the nasal sac this 
nerve leaves the nasal cavity at a foramen in the prenasal wall, 
but apparently does not pierce this wall. Kulczycki (1960) found 
no traces of the orbitorostral passage in his material of Porolepis, 
but he did find a blind canal leading from the nasal cavity into 
the prenasal wall ; thii> canal, which Kulczycki terms the ' ' para- 
apical canal," has, however, a different orientation from that 



c.l.I, 




A. #27 



#29 




C. #33 



D. #36 



Figure 8. Ectosteorhachis. Right nasal cavity, anterior division. #27, at 
tip of snout; #29 showing anterior margin of vomer; #33 showing 
anterior margin of external naris; #36 through naris. 



338 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



described by Jarvik, and in Kulczycki's opinion could only have 
contained a blood vessel. 

We may conclude that the pattern of the ramus profundus V is 
essentially similar in all Rhipidistia. 

Fifth cranial nerve: ramus maxillaris. Jarvik (1942) stated 
that in Porolepis this nerve did not reach as far anteriorly as 
the nasal region but terminated in the orbit. Kulczycki, however, 
claimed that there is evidence, in the form of a groove in the 
lateral nasal wall (Kulczycki, 1960, p. 92), that there was a 
truncus infraorbitalis extending into the nasal region. 

In Eusthenoptero7i, Jarvik (1942, p. 477) traced certain 
branches of the ramus maxillaris but only part of his restoration 
is based upon the positive evidence of endocranial canals. AVhat 
little I have been able to discover of the ramus maxillaris in 
Ectosteorhachis shows that it is generally similar to that of 
Eusthenopteron, but in most major respects our knowledge of this 
nerve in Rhipidistia is rather unsatisfactory. 





Figure 9. Ectosteorhachis. Right nasal cavity, median division. #39 
througli ijosterior part of external naris; #44 through crista lateralis; 
#46 and #47 showing beginning of entry of the olfactory tract canal 
into the posterior median recess. 



THOMSON: Kllll'IDlSTIAN SNOUT 339 

The seventh cranial nerve: nniiKs ophfJialmicus super ficialis. 
Ill Eusthcnopieron this ramus passes from the orbit through the 
postnasal wall and out onto the dorsal surface of the endoeranium 
in a canal which has no connection Avith the lumen of the nasal 
cavit3^ In EcfosfcorJiachis the path of the nerve is exactly the 
same, although Roiiier (19.37, fig. 8) mistakenly described the 
nerve as entering the nasal cavity. In both genera there may be, 
within the postnasal wall, a small canal connecting this nerve 
canal with that for the profundus V. 

According to Jarvik's (1942) interpretation of the structure of 
Porolcpis, the ramus ophthalmicus superficialis does not enter 
the nasal cavity, but Kulczycki (1960) presents evidence that 
the nerve does enter the cavity, either via a separate canal of its 
own or through that for the profundus V nerve, and that it passes 
along the dorsomedial part of the nasal cavity giving off branches 
through the endoeranium to the supraorbital lateral line canal. 
These branches are the ones that Jarvik (see above) attributed 
to the profundus V nerve. 

Seventh cranial nerve: ramus huccalis lateralis. Nothing is 
known concerning this nerve in Porolepis. Jarvik believed that 
it might have passed through the orbitorostral passage (the exist- 
ence of which has been disputed by Kulczycki). The situation 
in Eusthcnopteron is also vague although Jarvik (1942, pis. 11, 
12 and 13) described a gap between the dermal bones and the 
nasal capsule in which such a nerve might have passed. Ecto- 
steorhachis differs from Ensthenopteron in that the infraorbital 
lateral line canal is situated ventral to the level of the solum 
nasi, and the rather meagre evidence available indicates that the 
nerve may have been contained in the dermal bones of the 
anterior cheek region. 

Seventh cranial nerve: ramus palatinus. This nerve seems to 
have occupied exactly the same position in Porolcpis, Ensthenop- 
teron and Ectosteorhachis. 

Anastomoses in the nervous system. The two main groups of 
living Amphibia, Anura and Urodela, are characterized and may 
be distinguished by distinct patterns of anastomoses between 
the palatinus VII, maxillaris V and profundus V nerves (e.g. 
Cogliill, 1902) . Jarvik has attempted to show that the Rhipidistia 
of the families Porolepidae and Holopt.vchidae agree in this 
respect with the Urodela, and that the families Osteolepidae and 
Rhizodontidae agree wdth the Anura. A main point in Jarvik's 
thesis is the position of the anastomosis between the palatinus 



340 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



VII and the maxillaris V nerves, behind the nasal capsule in the 
Anura and medial to the choana in the Urodela. 

Unfortunately, the evidence concerning possible anastomoses 
in the Rhipidistia is rather incomplete, although Jarvik (1962) 
states that he has found new evidence in the anatomy of the poro- 
lepid Glyptolepis to confirm his original suggestions. My material 




Figure 10. Ectosteorhachis. Left nasal cavity. Series of sections through 
posterior part of the cavity, showing the postnasal wall and the associated 
nerve canals. 



THOMSON : RHIPIDISTIAN SNOUT 341 

of Ectosfcorhachis sheds little light on the problem ; there is no 
indication of a connection between the palatinus VII and the 
maxillaris V as they pass through the vomer or in the space be- 
tween the vomer and the palato-quadrate. 

The canal for the ramus maxillaris V, as it passes through 
the vomer, gives off one, sometimes two, fine canals to the dorsal 
surface of the bone, but since the solum nasi is not preserved, I 
cannot tell whether they might represent evidence of an anasto- 
mosis with tlie branches of the profundus V in the nasal cavity. 
They may liave carried small vessels. 

Both the profundus and maxillary rami of the fifth cranial 
nerve of Ectosteorhachis have branches which, as in Eusthenop- 
teron, terminate close together in the most dorsal part of the 
anterior palatal recesses. It is not possible to tell whether or not 
these nerve branches anastomosed here, although Jarvik states 
tliat this was the case. 

In summary, we may conclude that in all major respects in 
which it is fully known, the pattern of the nervous system is 
essentially similar in Ectosteorhachis, Eusthenoptcron and Poro- 
lepis. 

The Vascular System of the Snout 

No thorough review of the vascular system of the snout of 
Rhipidistia may be made, since the only genus in which it is 
even moderately well-known is Ectosfcorhachis. Kulczycki (1960, 
fig. 5) attempted a reconstruction of the Avascular sy.stem of 
Porolcpis, but this must be treated with reservation. He did, 
however, find a trace of a canal which might have carried a vena 
cerebralis anterior — described elsewhere only in Rhizodopsis^ 
(Save-Soderbergh, 1936). 

What little Jarvik was able to restore of the vascular system 
of Eusihcnoptcron (1942, p. 480) seems to agree fairly Avell with 
the arrangement in Ectosteorhachis. 

COXCERNING A DIPHYLETIC ORIGIN OF THE 
TETRAPODS from WITHIN THE RHIPIDISTIA 

Reference has been made throughout this work to the distinc- 
tions that Jarvik (1942) lias drawn between the genera Poro- 
lcpis and Eusthenoptcron with respect to the detailed anatomy 



1 I lirtvp SOPH thp sppciniPii stiidipd by Siive-Siidprliprtrh. Itut sim-p hp tispd thp 
"shatter technique" it is now impossible to learn anytliiii;; further from 
the specimen. 



342 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

of the snout region. From his study of the snout anatomy of 
the Gnathostomata Jarvik drew the following conclusions : 

1. That the four families of Rhipidistia may be considered 
to belong in two highly distinct groups: the "Porolepiformes" 
(comprising the families Porolepidae and Holoptychidae) and 
the "Osteolepiformes" (comprising the Osteolepidae and the 
Rhizodontidae). 

2. That the two major groups of Recent Amphibia, Urodela 
and Anura, differ greatly from one another in their snout anat- 
omy and must be considered to have arisen separately from 
different fish ancestors. 

8. That the Urodela differ from the Anura in exactly the 
same characteristics as the "Porolepiformes" differ from the 
" Osteolepif ormes, " and that the Urodela and Anura are direct 
descendants of the "Porolepiformes" and "Osteolepif ormes" 
respectively. 

The anatomical study of Ectosteorhachis set down above pro- 
vides us with a body of new evidence concerning the anatomy 
of the "Osteolepif ormes" which had previously been known 
only from study of Eusthenopteron. It is now possible to dis- 
cuss proposition 1 (above) in considerable (comparative) detail. 
Discussions of the interrelationships of the Amphibia belong 
elsewhere than in this paper; Parsons and Williams (1962 and 
1963), Baton (1959), Schmalhausen (1959), Szarski (1962) and 
others have discussed the evidence for and against a fundamental 
separation of the Urodela and Anura. With respect to such 
discussion it should be noted that the ancestry of the Recent 
Amphibia is known only from very incomplete palaeontological 
evidence and discussion relies heavily on evidence from the 
anatomy of living forms. I shall confine myself to a considera- 
tion of the evidence, in the snout anatomy, for a separation of 
the Rhipidistia into "porolepiforms" and " osteolepif orms" 
with special regard to the phylogenetic implications of this pro- 
posed separation. 

In his summary of supposed distinctions between the "Poro- 
lepiformes" and "Osteolepif ormes" Jarvik (1942, p. 489, et 
seq.) enumerated some 26 points by which Porolepis (and thus 
the "porolepiforms") might be interpreted as differing from 
Eusthenopteron (and thus, typically, the "osteolepif orms"). I 
propose now to examine each of these points in turn, in the light 
of the new evidence presented in the preceding pages. 

Several of the 26 points overlap each other and we may group 



THOMSON : RIIIPIDISTIAN SNOUT 343 

together first those dealinj; with the nature of the anterior 
palatal recesses and the "general arrangement of the ethmoid 
endoeranium. 

1. "The internasal wall in Eiisthenopteron is narrow and 
forms a solid nasal septum. Tlie internasal wall in PoroUpis is 
broad and lodges both the ethmoidal part of the cranial cavity 
and the paired cavum interna.sale" (1942, p. 489)/ 

2. "The divisio prenasalis communis is longer and narrower 
in Eusthenopteron than in Porolepis. On the latei-al parts of 
its lower face in Eusfhenoptvron are a pair of shallow, ventrally 
open prena.sal pits, situated far apart from each other; to these 
there is no equivalent in Porolepis. In Porolepis, on the other 
hand, the divisio prenasalis communis lodges the paired and 
comparatively deep cava prenasalia, which form the direct an- 
terior continuation of the cava internasalia and are situated 
close to each other" (1942, p. 489). 

3. "Point three" states that the "shallow paired" anterior 
palatal recesses in Eusthenopteron contained intermaxillary 
glands directly equivalent to those found in the anterior part of 
the palate in the Anura (p. 489, cf. p. 506) and that the cava 
internasalia of Porolepis contained intermaxillary glands ar- 
ranged in the same manner as in Urodela (p. 489, cf. p. 400). 

4. "The nasal cavities are fairly close to one another in 
Eusthenopteron, whereas they lie far apart in Porolepis" (p. 
489). 

26. "The anterior palatal fenestra in Eusthenopteron is 
comparatively small, lies entirely in front of the vomers under- 
neath the divisio prenasalis communis, and does not form the 
ventral opening of any large cavity. The anterior palatal 
fenestra in Porolepis is large, lies chiefly between the vomers 
underneath the internasal wall, and in it are seen the ventral 
openings of the cava internasalia and prenasalia" (p. 493). 

It should be noted that Jarvik distinguishes in his terminol- 
ogy between the apical pits and their "openings" the anterior 
palatal fenestrae; I prefer to use the term "anterior palatal re- 
cess" for the whole structure. Jarvik states that there are a pair 
of "prenasal" (equals "apical") pits in Eusthenopteron; but 
these are merely the two halves of an essentially undivided 
anterior palatal recess (cf. Jarvik, 1942, fig. 56). In Ectosteo- 
rhachis the anterior palatal recesses are definitely paired, and 



iln this ami the following quotations, ahlireviations and roferences to figures 
in the original text have been omitted. 



344 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

this is the case in Megalichthys and Pandcrichthys, as well as in 
Porolepis and Holoptychins. It has been noted above that the 
cava internasalia of "porolepiforms" and the anterior palatal 
recesses of "osteolepiforms" are homologous structures and that 
their characteristic nature reflects only the nature of the teeth 
at the tips of the lovs^er jaw rami. Thus there is a difference in the 
shape of the recesses in the two groups, but, since no glandular 
structures are involved, comparisons with the Eecent Amphibia 
are not justified. 

It has been noted also that the presence or absence of an 
ethmoid division of the cranial cavity — the pars ethmoidalis 
cranialis — is of random occurrence in the families of Rhipidistia 
and does not characterise any particular group. 

As has been pointed out in a previous paper (Thomson, 1962), 
the internasal wall in the "osteolepiforms" may be broad or 
narrow and there is no evidence to support the theory that the 
presence or absence of the cava internasalia or the pars eth- 
moidalis cranialis is correlated simply with the relative width of 
the internasal wall or the relative size of the nasal sacs (cf. 
Schmalhausen, 1959; Romer, 1962; Szarski, 1962). 

5. "The lamina nariochoanalis is in EustJienoptcron formed 
by the lateral nasal wall, in Porolepis both by the lateral nasal 
wall and an adjacent part of the solum nasi" (1942, p. 490). 

The solum nasi is not preserved in Ectosteorhachis. But 
whereas in the postehoanal region the lateral nasal wall curves 
slightly underneath the nasal cavity (Fig. 9, A, B), in the 
choanal region this slight ledge is not present (Fig. 8, A, B), and 
this may indicate that the lamina nariochoanalis was formed 
only by the lateral nasal wall. 

6. " Eusthenopfcron has no equivalent to Seydel's palatal 
process in Porolepis" (p. 490). 

Jarvik's identification of a small backwardly directed process 
on the anterolateral margin of the choanal aperture in the solum 
nasi of Porolepis as an homologue of the Seydel's palatal process 
of Urodela has been criticized by Kulczycki (1960) who has 
pointed out that if the subnarinal crest of Porolepis (see above) 
is homologised with the crista rostrolateralis of Urodela, then 
the small choanal process which lies "along its prolongation" is 
in a different position from that of Seydel's palatal process in 
urodeles. The process was not seen in Ectosteorhachis. 

7. "The fenestra endonarina anterior and the fenestra endo- 
choanalis are comparatively large in Eusthcnoptcron" (p. 490). 



THOMSON: IMIIIMDISTIAN SNOUT 345 

This does not seem a character of great phylogeiietic impor- 
tance. Ill Ectosteorhachis the fenestra endonarina is relatively 
slightly smaller than that of Eusthenopteron; the fenestra endo- 
choanalLs is of the same relative size. 

8. "'The fenestra endonarina posterior in Eu.sth()ioj>lcron is 
an opening in the postnasal wall leading backwards to the 
anterior ventro-lateral part of the orbit, and is separated ven- 
trally b}^ an endoskeletal bridge from the fenestra endochoanalLs ; 
in Porolcpia it lies in the lateral nasal wall and is continuous 
ventrally w^ith the fenestra endochoanalis" (p. 490). 

The posteroventral fenestra of Ectosteorhachis corresponds to 
the opening in the postnasal wall of Eusthenopteron which Jar- 
vik has homologised with the posterior external naris of Poro- 
lepis. It is difficult to tell whether Jarvik's proposed homology 
is justified or not ; it seems to me that this fenestra may pos- 
sibly have been one of the main openings through which the 
venous vessels left the nasal cavity and it is not impossible that 
nerve branches pa.ssed through it. Jarvik assumed that this fen- 
estra connected by means of a duct (the forerunner of the iiaso- 
lachrymal duct [1942, p. 537]) with the orbit but since the 
soft anatomy is not preserved there is no way of checking this 
hypothesis. 

It is interesting to note that Vorobjeva (1960a) has described 
the osteolepid Panderichthys as having two external nares, the 
posterior of which is confluent with the endochoanal aperture. 
If this observation is substantiated this genus may thus represent 
some sort of link between the "Porolepiformes" and the "Osteo- 
lepiformes" wath respect to this important character. 

14. Point 14 refers again to the difference in the relative 
positions of the posterior external naris in Porolepis and its 
"homologue" in Eusthenopteron, and mentions again tlic jios- 
sible homology of this structure in Eusthenopteron with the 
tetrapod nasolachrymal duct. This has been dealt with above. 

9. "No canal corresponding to the nasobasal canal in Eusthen- 
opteron exists in Porolepis. On the other hand the orbitorostral 
passage and the canal c.vl in Porolepis have no equivalents in 
Eusthenopteron" (p. 490). 

The nasobasal canal carried the terminal branch of the ramus 
medial is narium of the profundus V nerve through the anterior 
nasal wall into the anterior palatal recess in Eusthenopteron; 
a similar canal is present in Ectosteorhachis. As mentioned 
above, Kulczycki (1960) has noted a canal in Porolepis also 



346 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

which may correspond to this canal. 

The orbitorostral passage was not found in Ectosteorhachis. 
Knlezycki could not find this passage in his material of Poro- 
lepis. 

The "canal c.vl" is .something of an enigma; it lies in the 
lateral part of the postnasal wall of Porolepis and was supposed 
by Jarvik to carry a lateral branch of the profundus V nerve. 
However, it could very possibly have contained a blood vessel, 
particularly a vein, draining the nasal cavity. It is not present 
in Ectosteorhachis. 

10. "In Eusthenoptcron there is a single nerve-canal leading 
upwards from the nasal cavity to the dorsal face of the ethmoidal 
region ; in Porolepis a great many nerve-canals ascend from the 
nasal cavity to the dorsal face of the ethmoidal region, piercing 
the dorsal part of the medial nasal wall, the adjacent part of 
the prenasal wall, and the medial parts of the tectum nasi" (p. 
490). 

Point 19 refers to the same subject: "The n. profundus in 
Eusthenoptcron was comparatively weakly developed. . . . The 
n. profundus in Porolepis was strongly developed. ... In the 
nasal cavity the medial nasal branch divided into numerous 
dorsal branches" (p. 491-492). 

As has been noted in the previous discussion, the ramus pro- 
fundus of the fifth cranial nerve seems to be developed in 
approximately the same manner in Porolepis, Eusthenopteron 
and Ectosteorhachis. The canals passing through the dorsal wall 
of the nasal capsule of Porolepis seem to pertain to the ophthal- 
micus superfieialis VII nerve rather than to the profundus V. 
Thus, whereas the rami profundi of "Porolepiformes" and 
" Osteolepif ormes " are similar, there may be a difference in the 
path of the ophthalmicus superfieialis nerve — within the nasal 
cavity in Porolepis, and external to the nasal cavity in Eusthen- 
opteron and Ectosteorhachis. 

11. "The postnasal wall is pierced in Eusthenopteron by a 
single and not particularly wide profundus canal; in Porolepis 
by a wide medial and one or several narrower lateral profundus 
canals" (p. 490). 

We have noted above that there may be some variation in the 
number of canals through which the profundus nerve enters the 
nasal cavity. 

12. 13, 15. Points twelve and thirteen deal with the apparent 
subdivision of the chamber of the nasal capsule into recesses by 



TIIOMSOX : IMIIIMDISTIAX SXOl'T 347 

tiic presence of various ridyes and crest.s on the medial surfaces 
of the walls. I'oiiit 15 may also be discussed here, since it states 
that "The large diflferences in the nasal cavity show that there 
must liave been considerable differences [between Eusthenopteron 
and Porolepis] in the develoj)nient of ihe nasal sac" (pp. 490- 
491). 

The subject of the ridges and crests of the nasal capsule has 
been reviewed above and we have seen that the conditions in 
Porolepis, Eustlienopteron and Evtosteorhachis may possibly be 
related to each other. The processus intermedius (or its homo- 
logue) may be present in Porolepis as well as in Eusthenopteron 
and the subnarinal ridge seems to be present, slightly modified, 
in all three genera. 

It is not possible to decide with any degree of certainty 
whether or not the apparent morphological subdivisions of the 
nasal capsule represent any functional anatomical features of 
the nasal sac. For example, the ventromedial recess of Eusthe- 
nopteron corresponds exactly to that of Ectosteorhachis, but 
whether this recess of the nasal cavity contained a diverticulum 
of the nasal sac, and whether such a diverticulum, if present, 
would have contained Jacobson's organ (cf. Jarvik, 1942, pp. 
483, 536) cannot be decided from the fossils alone. And while 
answers to such questions may be formulated from comparisons 
with the Recent Amphibia, the objective purpose of the study 
would then be defeated. 

16. "The forebrain in Eusthenopttron was of approximately 
the same breadth as the diencephalon ; . . . The bulbi olf actorii in 
Eusthenopteron lay close to one another immediately in front 
of the hemispheres, whereas in Porolepis they were situated far 
apart at the lateral sides of the hemispheres" (p. 491). 

This apparent distinction arises from interpretation of the 
pars ethmoidalis cranialis of Porolepis as having contained the 
"hemispheres of the forebrain." In fact, available evidence now 
indicates that the pars ethmoidalis cranialis, which is of random 
occurrence throughout the Rhipidistia, did not contain Q-wy part 
of the brain anatomy, and that the brain of Porolepis was 
probably not greatly different in overall configuration from 
that of Eusthenopteron. 

17. "The lateral parts of the snout were in Eusthenopteron 
supplied mainly by the r. maxillaris V, in Porolepis mainly by 
the n. profundus" (p. 491). 

There is no doubt that in many adult Urodela, such as 



348 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Salamandra, which Jarvik took as his example for the group 
(Francis, 1934), the maxillaris V terminates in the orbit, as 
Jarvik has suggested is the ease in Porolepis. But in many 
aquatic Urodela and in the larva of Salamandra, in which the 
lateral line system is retained, the lateral line nerve — ramus 
buccalis lateralis VII — is bound into a "truncus infraorbitalis" 
with the maxillaris V nerve. This compound trunk passes an- 
teriorly right into the snout region, carrying the maxillaris V 
further anteriorly than in the terrestrial Urodela. It has often 
been supposed that the Khipidistia resembled, in their anatomy, 
the larvae of Amphibia more strongly than they resembled 
adult forms. If, therefore, any traces of the ramus buccalis 
lateralis VII nerve are to be found in the porolepid Rhipidistia 
then the po.ssibility cannot be excluded that the ramus maxillaris 
V was also present. 

18. "In Eusthenopteron the r. buccalis lateralis passes for- 
wards in the pons nariochoanalis laterally to the choana, giving 
off branches to the neuromasts of the anterior parts of the infra- 
orbital sensory canal. It terminated far anteriorly near the 
very tip of the snout. In Porolepis it presumably broke up 
into several terminal branches while still in the orbit. One of 
these terminal branches, which supplied the foremost neuromasts 
of the infraorbital sensory canal, went forwards through the 
orbitorostral passage medially to the choana" (p. 491, cf. Jarvik, 
1962). 

Kulczycki (1960) has queried Jarvik 's restoration of the 
orbitorostral passage in Porolepis. In Ectosteorhachis the nerve 
may possibly have passed through the dermal bones of tlie 
snout rather than between these bones and the nasal capsule 
as is the case in Eusthenopteron. Knowledge of the exact ar- 
rangement of the ramus buccalis lateralis in Rhipidistia is far 
from satisfactory. 

20. "The r. palatinus VII in Eusthenopteron pierced the 
anterolateral part of the vomer and during this part of its 
course it broke up into three branches ... In Porolepis the 
r. palatinus VII probably did not divide during its passage 
through the vomer . . ." (p. 492). 

The ramus palatinus VII did not branch during its passage 
through the vomer in Ectosteorhachis. In this genus, as in 
Porolepis, the nerve ran through the medial part of the vomer. 

21. Point 21 deals with the fact that Jarvik found traces of 
fusion between the tip of the palato-quadrate and the socket 



THOMSON : KMIIl'IDISTIAX SNOTT 349 

for it ill the (MKlocraiiiuiii, in PJxstln iioph rtjii but not in I'oro- 
lepis (p. 492). 

In Ectosteorhacliis, as noted by Konier (H'.'^, p. 22). the 
notch for the reception of the palato-quadrate is not lined by 
periosteal lione, and thus in this respect Ectostroihachis agrees 
with Ensthenopteron. 

22. Point 22 states that the pineal opening, between the 
"frontal" bones (parietal bones) is characteristically present 
in "Ensthenopteron and other Osteolepiformes" but is absent 
in Porolepiformes. 

In the family Osteolepidae the i)ineai openinji' is present in 
Osteolepis and other Devonian forms, but absent in Megalich- 
thys and Ectosteorhachis. 

23. "The vomers in Ensthenopteron meet anteriorly in a 
median suture but their long posterior processes diverge and are 
separated from one another by the parasphenoid. Each vomer 
is provided with a descending tooth-bearing lamina. The vomers 
in Porolepis lie mainly in front of the parasphenoid. Their pos- 
terior parts are close to one another, but further anteriorly they 
diverge strongly. They have neither a posterior process nor a 
descending tooth-bearing lamina" (p. 492). 

The vomers of EctosteorhacJris, Megalichthys, (ihi}>t<)pi>)nns, 
and probably also Osteolepis and Thnrshis (all osteolepids) lack 
the posterior process of Ensthenopteron (Th( mson, 1964 ) ; the 
vomers in each of these genera lie anterior to the parasphenoid. 
It seems quite possible, although not all genera are yet well 
enough known, that the posterior process of the vomer is a 
special characteristic of the Rhizodontidae. 

The vomers of Ectosteorhaehis but not Me(jalichthys have an 
anterior tooth-bearing lamina comparable to that of Ensthenop- 
teron. 

Discussion of the vomers is closely tied up with the next 
subject — the nature of the parasphenoid. 

24. "The parasphenoid in Ensthenopteron is narrow and 
goes forward underneath the ethmoi<la] region practically to the 
transition between the internasal wall and the divisio prenasalis 
communis. The parasphenoid in Porolcpis is broad and hardly 
extends forwards onto the lower face of the ethmoidal region" 
(pp. 492-493). 

In the family Osteolepidae a transition may be seen from 
Osteolepis through Megaliehfhus to Ectosteorhaehis in which the 



350 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

tooth-bearing median ridge of the parasphenoid becomes pro- 
gressively .shorter^ (cf. Thomson, 1964). One very likely ex- 
planation of the difference between the relative arrangements of 
the vomers and parasphenoid in "Porolepiformes" and "Osteo- 
lepiformes" is that their disposition on the anterior part of the 
palate is determined by the extent of the anterior palatal 
recesses which, as noted above, reflect in their turn the nature of 
the anterior dentition of the lower jaws. 

In the "Porolepiformes" the anterior palatal recesses are 
large and extend posteriorly between the vomers and the para- 
sphenoid, hence separating the vomers from one another and 
from the parasphenoid and limiting the anterior extent of the 
latter. With the evolution of the Osteolepidae (which temporally 
and structurally precede the Rhizodontidae), the anterior denti- 
tion of the lower jaws changed from a pair of symphysial tooth 
whorls (cf. Jarvik, 1962) to a set of simple tusks. Attendant 
upon the reduction of the anterior palatal recesses to a (paired) 
recess wholly anterior to the vomers and the tip of the endo- 
cranium, the parasphenoid came to extend to the tip of the 
palate and the vomers were free to extend medially to meet 
each other and the tip of the parasphenoid. In the Rhizodontidae 
the parasphenoid remained long and the vomers further became 
extended po.steriorly on either side of it. In the later Osteolepidae 
the tooth-bearing ridge of the parasphenoid became secondarily 
reduced (cf. Megalichthys and Ectostcorhachis in Thomson, 
1964). The vomers in the Osteolepidae do not seem to have 
become as strongly developed mesially as in Rhizodontidae; the 
vomer.s of Mcfiolichthys and Ectostcorhachis retain an approxi- 
mately triangular shape — with their "apices" directed mesially. 

As noted by Romer (1937), the parasphenoid of Ectostco- 
rhachis is in two parts, a narrow, median tooth-bearing lamina 
and a broad thin flange of bone spreading anterolaterally from 
the tooth-bearing ridge. The whole is fused to the endocranium. 
Unfortunately, it has not been possible to determine whether 
this condition is present in other " Osteolepif ormes. " 

25. "The fossa apicalis, intervomerine pit and intervomerine 
canal present in Eusthcnoptcron are all absent in Parole pis'' 
(p. 493). 

The intervomerine pit is the anterior opening of the inter- 
vomerine canal which in Eusthenoptcron opens into the median 



iThe speeimen of '•ThursiiiKf" (inured l).v .Tnrvik (1942. fig. (i2B) soeiiis to fit 
into this series between Ostcvlcpis and Megalichthys. 



TIIOIMSOX: RIIII'IDISTIAN SNOKT 351 

part of tlic antci-ior palatal recess, in I'Jctostcn-liachis, as in 
Porolfpis, the vomers do not meet in a median suture and thas 
no canal passing between them may be seen in the fossils. The 
significance of the intervomerine canal is unknown ; it may have 
contained a nerve, vessel, or duct of some kind. 

There are obvious limitations to the conclusions that can be 
drawn from a study of the snout apparatus alone ; a broader 
study of the entire anatomy of the llhipidistia might lead to 
results very different from those derived from this restricted 
series of data. Bearing in mind these limitations, however, it is 
})ermissible to reach some interim conclusions as to the relation- 
ships of the rhipidistian families to each other and to the 
tetrapods, from the evidence of the snout anatomy. 

In the preceding discussion of the evidences for Jarvik's 
theory of a basic division of the Rhipidistia, the results of 
comparative studies seem to show that very many of the 
characteristics used by Jarvik to distinguish the "Porolepi- 
formes" from the "Osteolepiformes" no longer support such an 
hj'pothesis. However, a limited number of the differences which 
he claimed are either corroborated by the comparative evidence 
or were not able to be compared in the material available for 
study. Thus the following features must still be considered as 
evidence for Jarvik 's theory : 

1. There seems to be a difference in the composition of the 
lamina nario-choanalis. 

2. There are differences in the courses of certain blood vessels 
and minor nerve branches. However, the evidence concerning 
most of these is in rather an unsatisfactory state, especially for 
Porolepis. 

3. A more distinct difference in the nervous system is that in 
Eui^thi nopteron and Ectosteorhachis the ramus ophthalmicus 
superficial is VII was seen to pass through the tectum nasi, 
whereas in Porolepis this nerve enters the nasal cavity. 

4. There seems to be a trend towards lack of mobility of the 
palatal articulation of the palato-quadrate complex. In both 
the osteolepid EctosteorJiachis and the rhizodontid Eusthcnop- 
teron the notch in the palate for the reception of the pars auto- 
palatina is not lined with periosteal bone, whereas in Porolepis 
it is. 

To these few differences in the nasal region may be added 
certain features which fall outside the scope of the present 
study. Jarvik (1962) has described differences in the structure 



352 BULLETIN : MUSEUM OF COMPAEATIVE ZOOLOGY 

of the branchial arch apparatus of Eusthenopteron and Glyp- 
tolepis. Investigation of the branchial arch apparatus of other 
rhipidistians has yet to be made. 0rvig (1957) has described 
the microscopic structure of the scales of the Rhipidistia, and 
Jarvik (1962) considers that the evidence presented by 0rvig 
further substantiates his interpretation of rhipidistian relation- 
ships. Another feature is the difference in the nature of the 
anterior dentition of the lower jaws (cf. Jarvik, 1962; Thomson, 
1962; and above). 

In discussing the significance of the various anatomical fea- 
tures of the Rhipidistia, it must be borne in mind that two 
separate discussions are involved; on the one hand, there is the 
problem of the classification of the Rhipidistia themselves, and 
on the other hand, there is the problem of the relationship of 
the Rhipidistia to the tetrapods. Jarvik has endeavoured to show 
that these two problems are but two sides of the same coin. He 
delineates two basic groups of fishes in terms, principally, of 
their supposed anatomical relationship to the two "separate" 
groups of Amphibia. However, the main conclusion of the pres- 
ent study must be that, on the evidence of the snout anatomy, 
the three families of Rhipidistia investigated (Porolepidae, 
Osteolepidae and Rhizodontidae) are constructed according to a 
common anatomical plan. Furthermore, and most importantly, 
this overall similarity in structure is particularly manifest in 
the majority of those characters (the pattern of the nervous 
system, nature of the internasal wall, etc.) which Jarvik con- 
sidered to be diagnostic of the specific relationships of the "poro- 
lepiforms" and urodeles, on the one hand, and the "osteolepi- 
forms" and the anurans, on the other hand. Thus, from the 
detailed review of the comparative anatomy of the rhipidistian 
snout, given above, we must come to the conclusion that there 
is no substantial evidence in these structures to sup])ort the 
supposition that any particular family of Rhipidistia is more 
closely allied to one particular group of Amphibia than to 
another. There is no evidence to support the particular diphy- 
letic theory of tlie origin of the tetrapods proposed by Jarvik. 

We may now turn to examine Jarvik 's proposition that the 
Rhipidistia comprise two separate stocks — "p()role]uform" and 
"osteolepiform." We may accept the fact that the families 
Porolepidae and Holoptychidae are very closely allied. But to 
balance the apparent distinctions between these fishes and the 



THOMSON: KHIi'IDISTIAN SNOUT 353 

combined Rhizodoiitidae and Osteolcpidae, noted in the preced- 
ing paragraphs, we may take note of the very numerous re- 
seml)]ances between the four families of Rliipidistia — resem- 
blances wliich indicate the es.sential unity of the group as a whole 
(Schmalhausen, 1959, 1960; Romer, 1902; Thomson, 1962; Szar- 
ski, 1962). Most importantly we may note that in certain fea- 
tures, such as the structure of the scales (0rvig, 1957), the 
configuration of the nasal apparatus, and possibly also the ar- 
rangement of the vomers and para.sphenoid on the palate, the 
Osteolepidae differ from the Rhizodontidae as greatly as they 
differ from the Porolepidae and Holoptychidae combined. Such 
considerations led Berg (1958) to consider the Rhipidistia as 
being made up of three main groups — the Porolepiformes, the 
Osteolepiformes and the Rhizodontiformes. Such a scheme seems 
more correctly to assess the interrelationships of the four fami- 
lies than does that of Jarvik. Assignation of ordinal rank to 
each group has the disadvantage of over-emphasizing the differ- 
ences between the families. A more satisfactory arrangement 
would be to consider each group as no more than a superfamily. 
In summary we may conclude : 

1. That the four families of Rhipidistia are, anatomically, a 
close-knit assemblage. 

2. The interrelationships of the Rhipidistia may not be ex- 
pressed by a simple separation of "Porolepiformes" and "Osteo- 
lepiformes," but rather the Rhipidistia may be thought to com- 
prise three superfamilies, the Iloloptychoidea, Osteolepoidea and 
the Rhizodontoidea, of equal rank. 

3. There is no evidence in the anatomy of the rhipidistian 
snout to indicate a diphyletic origin of the urodele and anuran 
Amphibia from within the Rhipidistia. 

LITERATURE CITED 

Berg, L. S. 

1958. System der rezenten und fosailen Fischartigen und Fische. 
Berlin, Deutscher Verlag, 310 pp. 

Bryant, W. L. 

1919. On the structure of Eusthenopteron. Bull. Buffalo Soc. Nat. 
Sci., 13: 1-23. 
COGHILL, G. E. 

1902. The cranial nerves of Amblystoma tigrinum. J. Conip. Neurol., 
12: 205-289. 
Eaton, T. H. 

1959. The ancestry of the modern Amphibia: a review of the evidence. 
Univ. Kansas Publ. Mus. Nat. Hist., 12: 217-240. 



354 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Feancis, E. T. B. 

1934. The anatomy of the salamander. Oxford, 381 pp. 
Holmgren, N. and E. A. Stensio 

1936. Kranium und Visceralskelett der Akranier, Cyclostomen und 
Fische. In L. Bolk ei alia, Handbuch der vergleichenden Ana- 
tomie der Wirbeltiere, vol. 4: 345-353. 

Jarvik, E. 

1937. On tlie species of Eusthenopteron found in Russia and the 
Baltic states. Bull. Uppsala Geol. Inst., 27: 63-127. 

1942. On the structure of the snout in crossopterygians and lower 
gnathostomes in general. Zool. Bidrag., 21: 237-675. 

1954. On the visceral skeleton in Eusthenopteron Avith a discussion of 
the palato-quadrate in fishes. K. Svenska Vetens.-Akad. Handl., 
(4) 5: 1-104. 

1962. Les Porolepiformes et I'origine des urodeles. Colloques Internat. 
du Centre de la Recherche Scientifique, Paris, no. 104: 87-101. 

KULCZYCKI, J. 

1960. Porolepis (Crossopterygii) from the Lower Devonian of the 
Holy Cross Mountains. Acta Palaeont. Poloniea, 5: 65-106. 
0RVIG, T. 

1957. Remarks on the vertebrate fauna of the lower Upper Devonian 
of Escuminac Bay, P.Q., Canada, with special reference to the 
porolepiform crossopterygians. Arkiv. ZooL, 10 (6) : 367-426. 
Parsons, T. and E. E. Williams 

1962. The teeth of Amphibia and their relation to amphDjian 
phylogeny. J. Morph., 110 (3): 375-390. 

1963. The relationships of the modern Amphibia : a re-examination. 
Quart. Rev. Biol., 38: 26-53. 

PiNKUS, F. 

1895. Die Hirnnerven des Protopterus annectens. Morph. Arbieten., 

4: 275-346. 
Romer, a. S. 

1937. The braincase of the Carboniferous crossopterygian MegaUch- 

thys nitidus. Bull. Mus. Comp. Zool., 82 (1): 1-67. 
1941. Notes on the crossopterygian hyomandibular and braincase. 

J. Morph., 89 (1): 141-160. 

1955. Herpetiehthyes, Amphibiodei, Choanichthyes or Sareopterygiif 
Nature, 176: 126. 

1962. Vertebrate evolution: a review. Copeia, 1962 (1): 223-227. 
Save-Soderbergh, G. 

1936. On the morphology of Triassic stegoeephalians from Spitz- 
bergen, and the interpretation of the endocranium in the 
Labyrinthodontia. K. Svenska Vetens.-Akad. Handl., (3) 16: 
1-181. 

SCHMALHAUSEN, I. I. 

1959. Concerning monopliyletisin and jjolyphylutism in relation to the 
problem of the origin of the land vertebrates. Bull. Mosk. 
Obshch. Isp. Pri. Biol., 64 (4): 15-33. (In Russian.) 



THOMSON: HHU'IDISTIAN SNOUT 355 

1960. Biological basis of the classification of the erossopteiygian fish. 
Palaeont. J. Akad. Nauk. U.S.S.R., 19C0, no. 1: iMT). (In Rus- 
sian). 
Stensio, E. a. 

1922. Notes on certain crossopterygians. Proc. Zool. Soc. London, 
1922: 1241-1271. 
Sternberg, R. M. 

1941. Cranial morphology of the I)evoni;ui crossoi)terygian Eaatlnnop- 
teron. Univ. Toronto Studies, Geol. Ser., no. 45: 1-48. 
SZARSKI, 11. 

1962. Origin of the Amphibia. Quart. Rev. Biol., 37: 189-241. 
Thomson, K. S. 

1962. Rhipidistian classification in relation to the origin of the 

tetrapods. Breviora, ]\Ius. Comp. Zool., no. 177: 1-12. 
1964. Revised generic diagnoses of the fossil fishes Mef/aliclithys and 
Ectosteorhachis (family Osteolepidae). Bull. Mus. Conij). Zool., 
131(9): 283-311. 
VOROBJEVA, E. I. 

1959. A new genus of crossopterygian fish — Plati/ccphallchthy.s from 
the Upper Devonian of Lovat. Palaeont. J. Akad. Nauk. 
U.S.S.R., 1959, no. 3: 95-106. (In Russian.) 
1960a. New facts about the genus Panderichthys from the Devonian 
of the U.S.S.R. Palaeont. J. Akad. Nauk. U.S.S.R., 1960, no. 1: 
87-96. (In Russian.) 
1960b. Concerning the systematic position of Eusthcnopteron wen- 
jucovi (Rohon). Palaeont. J. Akad. Nauk. U.S.S.R., 1960, 
no. 2: 121-129. (In Russian.) 
Watson, D. M. S. 

1926. The evolution and origin of the Amphil)ia. Phil. Trans. Hoy. 
Soc. London, (B) 214: 189-257. 
Watson, I). M. S. and H. Day 

1916. Notes on some Palaeozoic fishes. Mem. and Proc. Manchester 
Lit. Phil. Soc, 60 (1): 1-47. 

ABBREVIATIONS USED IN THE FIGURES 

a.cut.va. anterior cutaneous artery 

a.ni.r. anterior median recess 

ana. anterior nasal artery 

a.p.r. anterior palatal recess 

a.pr. anterior postrostral 

a.r. anterior rami (of profundus) 

c.ana. canal for anterior nasal artery 

cc.aa. canals through anterior nasal wall 

cc.mea. canals for median ethmoid arteries 

ch. clioana 

c.l. crista lateralis 

c.l.cut.va. canal for lateral cutaneous artery 



356 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



c.lat. canal for lateral nasal vein 

c.1.1. lateral line canal 

c.max. canal for maxillary V nerve 

c.m.cut.va. canal for median cutaneous artery 

c.mev. canal for median ethmoid vein 

c.o.s. canal for ramus ophthalmicus superfieialis VII 

c.pal. canal for palatine VII nerve 

c.pr.V canal for profundus V nerve 

c.r.ext. canal for ramus exterior (of profundus) 

c.ros.VII canal for ramus ophthalmicus superfieialis VII. 

c.r.r. canal for ramus rostralis (of profundus) 

ds. dermosphenotic 

e.n. external naris 

f.ap. foramen apicale 

f .cut.va. foramen for medial cutaneous artery 

ff.ros. foramina for ramus ophthalmicus superfieialis VII 

gr.c.l. groove on medial face of crista lateralis 

gr.prf. groove for profundus nerve 

gr.ros. groove for ophthalmicus superfieialis VII 

g.s.o.l. groove for supraorbital lateral line 

i.c.a. internal carotid artery 

i.o.c. canal for infraorbital lateral line 

i.o.l. infraorbital lateral line 

l.c.v. lateral canal in vomer 

l.cut.a. lateral cutaneous artery 

l.n.v. lateral nasal vein 

m.c.v. medial canal in vomer 

mea. median ethmoid arteries 

mev. median ethmoid veins 

m.pr. median postrostral 

n. nasal 

n.c. nasal cavity 

n.pq. notch for palato-quadrate 

n.prf. notch for profundus nerve 

n.ros. notch for ramus oplithalmicus superfieialis 

n.r.p. naso-rostro-premaxilla 

n.t. tube of external naris 

olf.c. connection of anterior cutaneous 

artery back to canal for olfactory tract 

olf.t. olfactory tract 

pa. parietal 

pal.a. palatine artery 

pin.f. pineal foramen 

pm.t. premaxillary tusk 

p.n. postnarial 

p.q. palato-quadrate 

p.rec. posterior median recess 



THOMSON: RHIPIDISTIAN SNOUT 357 



prf. profundus V nerve 

pr.n. prenarial 

p.v.f. parasphonoid 

ps. posteroventral fenestra 

r.ext. ramus exterior (of profundus) 

r.lii. ramus lateralis narium (of profundus) 

r.inax. ramus maxillaris V 

r.iiin. ramus medialis narium (of profundus) 

ros. ramus ophthalmicus superficialis VII 

r.pal. ramus palatinus VII 

r.r. ramus rostralis (of profundus) 

rr.a. anterior rami (of profundus) 

8.0.1. supraorbital lateral line 

V. vomer 

(Received May 10, 1963) 



Bulletin of the Museum of Comparative Zoology 
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THE ANGLES (SAURIA, IGUANIDAE) OF THE 
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THE ANGLES (SAURIA, IGUANIDAE) OF THE 
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Guadeloupeen Arch ipclayo^ 

By Jamks D. Lazkll, Jr. 



INTRODUCTION 

The archipelagfo which lies between Doiiiinica and Montserrat 
in the northern portion of the Lesser Antillean chain represents 
both a political and a geop:raphical unit. Part of the French West 
Indies, and of the Kepul)lic of France, it is comprised of four 
large islands — La Guadeloupe (often, though erroneously, called 
"Basse-Terre" for its capital city) Grande Terre, La Desirade, 
and Marie Galante — and a number of smaller islands : Ilet-a- 
Kahouanne, Ilet-a-Fajou, Uet-a-Cochons (ou Gouvernement), 
plus two island groups, Les lies da la Petite Terre, and Les lies 
des Saintes. Taken together, these islands may be referred to as 
the Guadeloupeen archipelago, namd for La Guadeloupe, the 
largest of them. 

The Guadeloupeen archipelago is not a geological unit. La 
Guadeloupe itself, about 25 miles long and 15 miles wide, contains 
a central spine of mountains that reach nearly 5,000 feet (1,467 
meters) above sea level. Many of these mountains are still ac- 
tively volcanic, and attest to the process which has built this 
land mass. Grande Terre, on the other hand, though nearly as 
large in area, is low, rather fiat throughout, and comprised of 
oceanic limestone overlying an ancient volcanic base. Following 
Davis (1926), La Guadeloupe may be taken as representative 
of the "first cycle" islands of the Lesser Antilles, and Grande 
Terre as representative of the "second cycle" islands. 

The first cycle islands are composed of volcanic rock and have 
never been submerged and recapped wath limestone. Along 
with La Guadeloupe, Les lies des Saintes and Uet-a-Kahouanne 
are members of thi.s group ; Les lies des Saintes and Ilet-a-Ka- 
houanne are, however, no longer actively volcanic, and are the 
severely eroded remnants of once larger land areas. The latter 
islands may be considered as among the oldest remaining in the 
first cycle. 

The second cycle islands, though of volcanic origin, have 
subsequently been submerged and capped with limestone. Grande 
Terre, Ilet-a-Cochons, La Desirade, Les lies de la Petite Terre, 
and Marie Galante, taken together, constitute the southernmost 

1 The Anolfs of the Eastern Caribbean. I'art VII. 



362 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

limit of the second cycle in the Lesser Antilles. There is no 
information available to me on their relative ages. 

Ilet-a-Fajoii is in reality an extensive mangrove swamp. It 
lies in the shallow Grande CuI-de-Sae Marin, and appears to be 
a product of the predominant northeast wind : a collection of 
detritus banked up along a strip of coral reef. Its northern 
edge is a few meters above sea level, and is, even during the 
rainy season when I Avas there, a dusty bit of liarren desert. 
Squeezed between this small area of desert and the sea is a 
narrow band of scrub and thornbush wdiere the anoles of Ilet-a- 
Fajou are to be found. 

In general, Anolis are found throughout the archipelago 
wherever more than herb-stage vegetation occurs; they are not, 
however, apparently found on the highest peaks of La Guade- 
loupe. In the last revision of Lesser Antillean AvoJis, hy Under- 
wood (1959), the five named taxa of the Guadeloupeen archipelago 
were reviewed; marmoratus, ferreus, and speciosvs (with two 
subspecies) were considered distinct at the species level from 
other Anolis of the himaculatus species group. A fifth form, 
alliaceus, was considered to be a subspecies of himaculatus itself 
(the type locality of himaculatus is St. Eustatius, separated by 
four islands on three banks and several hundred miles from the 
Guadeloupeen archipelago), and a sixth form, the Desirade 
anole, was granted specific status, but not described and named. 
In his discussion of alliaceus, Underwood (p. 200) notes that 
Williams regarded that form, sensu Underwood, to be a composite 
of two distinct species. Therefore, Underwood had available to 
him at the time of his revision representatives of a maximum of 
seven taxa from five islands of the archipelago. 

The salient features of Underwood's revision may be sum- 
marized as follows : he regarded assignment to species or sub- 
species level of isolated, allopatric forms to be largely a matter 
of taste ; he believed color characters to be of primary importance 
in species recognition, and squamation characters to be "only 
indirectly significant by-products of species differentiation" (p. 
193) ; he preferred to regard populations as subspecies when 
monophyletic relationship was "clear"; and finally, he believed 
that the general degree of morphological similarity and difference 
between two forms could be used as a reasonable indication of 
the clarity of their relationship. 

Although I do not feel that there was consistent adherence 
to these principles in the annotated list of forms of the eastern 



LAZELL : GUADELOUP^EN ANGLES 363 

Caribbean presented by Underwood, the nuilorial he had avail- 
able was extremely scant, to say the least, and it is tlicrefore 
only to his last principle that 1 take exception at this point. 

The validity of "degree of similarity" as an indication of 
relationship needs especial consideration before it can be used 
in the species group. In particular, it is demonstrably invalid 
with regard to sympatric species of Anolis in the West Indies. 
An example of this point can be found in Underwood and Wil- 
liams (1959) with respect to the grahami-opalimis group in 
Jamaica: here Underwood (p. 47) himself acknowledges that 
the two intergrading subspecies of Anolis grahami are, in fact, 
considerably more morphologically divergent from each other 
than either is from the sympatric Anolis opalinus. 

To me it seems that a principle such as "degree of similarity," 
so easily rejected for sympatric forms, should not be considered 
valid when applied to allopatric forms in the species group. 
"Degree of similarity" is in constant use with higher taxonomic 
categories, but one is reminded of Simpson's (1961) discussion 
of the fact that higher taxonomic categories are entirely man- 
made assemblages, and therefore of a wholly arbitrary nature. 
Morphological "degree of similarity" has, for these reasons, not 
been used in the following revision and description of Guade- 
loupeen Anolis as an indication of specific or subspecific rank. 
Acceptance of the "principle" would lead to the wrong conclu- 
sions in more than half the cases considered. 

In revising the Guadeloupeen forms, and describing the previ- 
ously unknown ones, I have used instead Simpson's definition 
of the '"evolutionary species," in which the principal criterion 
is continuity of evolutionary role. 

As Simpson carefully points out, geographic isolation tends 
to break the continuity of evolutionary role ; thus isolated, allo- 
patric forms may well be distinct species, even wiien derived 
frum the same ancestor. In assigning populations to subspecific 
rank under the same species, in the Guadeloupeen archipelago, 
1 admit the following as evidences of continuity of evolutionary 
role : 

1. Actual intergradation : where there exists between two 
distinct populations occupying different geographic areas a zone 
in which "intergrade" individuals assure continuous gene flow 
between the two extremes. 

2. The presence of a morphologically intermediate population, 



364 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

when isolated by a topographical barrier, between the two ex- 
tremes. This would include a series of geographically isolated, 
allopatric^ populations which proceed in a stepwise sequence 
relative to the development or degeneration of characters in 
such a way that the second is intermediate betAveen the first and 
third, the third is intermediate between the second and fourth, 
etc. — even when the forms involved are 100 per cent distinct 
from each other. A sequence of forms such as this will be re- 
ferred to hereafter as a "stepped-cline" series, and in such cases 
I regard each member of the series as worthy of nomenclatural 
recognition providing it is diagnostically distinct from the others. 
In cases where it is not diagnostically distinct from the others 
I refer to it as though it were a population of actual intergrades. 

3. Tenable evidence that the extant differences are the result 
of a trend in an isolated population of the species under which 
the different form is to be included. A case like this requires, 
to my way of thinking, the presence of some third population 
which, though demonstrably a member of the species involved 
on other bases, sets a precedent for evaluation of the sort of 
differences noted in the form presumed to have resulted from 
this trend. Examples of this are comparatively rare, and, I 
believe, constitute the only cases in which assignment to rank 
may degenerate to a matter merely of personal taste. 

It is my belief, based on seven years of observing West Indian 
Anolis, both in the field and in the laboratory, that no two 
samples of specimens, no matter how different they appear, may 
he unfailingly allocated to correct rank relative to each other 
within the genus unless they are sympatric, or unless samples 
of geographically intermediate populations are available and 
considered. In the latter case, it must be remembered that, 
should the samples be found to represent members of the same 
evolutionary species, their status as distinct subspecies Avill 
depend entirely on whether or not they represent diagnostically 
homogeneous, clear-cut geographic segments of the same species. 
Two ends of a gradual cline, not broken into segments, or whose 
segments are not diagnostically distinct, are not herein regarded 
as nomenclaturally distinct, no matter how different from each 
other. 

This is to say that a great deal of geographic variation iritliiii 
species does not produce the sort of segmental units irc can 

' The ttTiii "iill<]i)atrie" is here used sriisu stricto, ami i.s not to Ix- cont'iist'd 
with "pnrapatric." 



LAZEIJj : GUADELOUPEEN AXOLES 365 

usefully refer to as- "subspecies." Tho fact tluit a lar^re number 
of geographic units which can bo usefully regarded as subspecies 
are present in the Guadeh)up<''en ai-chipelago is genuinely re- 
markable, and is considered iiiidor "' Hvolutionary Discussion." 

MKTIIODS OF ANALYSIS 

The primary materials for this study are 792 specimens of 
Anolis collected from 77 localities on 13 islands throughout the 
archipelago. During August and September of 1961, 75") speci- 
mens were collected from 73 localities, and the additioiml 37 
specimens from four localities Avere collected in September of 
1962 on two islands, to insure coverage of all distinctive popula- 
tions. Specimens already in the Museum of Comparative Zoology 
(MCZ) were considered only after the living matei-ial had been 
examined. 

Specimens were preserved, tagged, and catalogued only after 
careful color notes had been taken. Color sketches were made in 
the field of all the forms involved. All of the forms described 
herein were initially recognized on the basis of color characters. 
Scale characters, though often noticeable in the field, were not 
considered in detail until the specimens were studied in the 
laboratory. Fortunately, those characteristics of squamation 
which were noted in the field, as well as others discovered since, 
vary concordantly with the color characters, and are helpful in 
distinguishing the forms. 

In attempting to render the females of the various forms more 
readily distinguishable, I have classified the middorsal i)atterns 
represented among female Guadeloupeen Anolis under five head- 
ings (see Figure 1) : 

1. Brol-en: A pale middorsal stripe set off from the dorso- 
lateral coloration by a coalescing series of dark spots. 

2. Striped: A pale middorsal stripe set off by a continuous 
dark border on each side. 

3. Ladder: A middorsal pattern with dark transverse con- 
nections across the pale middorsal stripe from one border to the 
other. 

4. Mottled: Light and dark middorsal markings not forming 
a special pattern. 

5. Obsolete: A dark middorsal zone, without markings, con- 
trasted to the dorsolateral coloration. 

It was noted in the field that the females of the forms involved 
were not only distinctive relative to each other, but that the 



366 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



\ / 








Figure 1. Middorsal patterns of female Anolis marmoratus : 1. broken 
(MCZ 71284) ; 2. striped (MCZ 70945) ; 3. ladder (MCZ 70676) ; 4. mottled 
(MCZ 71356); 5. obsolete (MCZ 71210). See text for explanation. 



LAZELL : GUADELOUPEEN ANGLES 367 

total coloi-atioii and pattern of the feiualcs wa.s often more con- 
stant witliin any one taxon than these features in the males. 
T'^nderwood did not deal with females simply beeanse he rejjarded 
them as beinfj: only occasionally distinctive. 1 have not found 
this to be the case; on the contrary, the females in life are just 
as distinctive as the males. Also, males of some forms, from 
any one locality, are apt to show such a bewilderino- array of 
spots and marl)les, varying from many and bold to very few 
and vague, that they can be genuinely confusing until one has 
come to recognize the constant, and often rather subtle, charac- 
ters common to all specimens. Females were not found to differ 
from males with respect to squamation characters. 

The following- general characteristics of scjuamation were 
considered for all forms : 

1. Scale size. That striking differences in scale size existed 
between several of the forms was noted in the field. In an 
attempt to render this character diagnostically useful, several 
methods of quantification were used. First, the number of dorsals 
in the standard distance (defined as the distance from the 
center of the eye to the tip of the snout) was counted and 
plotted against the number of ventrals in the standard distance 
in a two-variable linear graph. This method showed the differences 
anticipated, but wa.s open to the criticism that head-body pro- 
portions might vary among the several forms. Consequently, 
the ratio of standard distance to snout-vent length was calcu- 
lated for all specimens. The relationship proved quite constant: 
the standard distance is between 16 and V.) per cent of the snout- 
vent length in all Guadeloupeen anoles, except very old and very 
young .specimens ; in these exceptions the standard distance may 
be as little as 14.5 per cent of the snout-vent length. As a further 
check on the accuracy of the standard distance count method, 
the around-the-body count approach was utilized. Around-the- 
body counts, midway between axilla and groin, were made on 
all specimens from Ilet-a-Kahouanne, Ilet-a-Fajou, Les lies de 
la Petite Terre, Marie Galante, and Les lies des Saintes, as well 
as in scattered series from various localities on La Guadeloupe, 
Grande Terre, and Desirade: some 220 in all. This method 
showed the same differences between the same forms, and was 
sufficiently tedious to increase my appreciation of the practical 
value of the standard distance count. 



368 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



In the following diagnoses of each form, the range of dorsal 
scales counted in the standard distance, based on all the speci- 
mens available from my collections, is given. The count is made 
between six and eight scales lateral to the middorsal line, and 



KiihoLianne 





La D^sirade 



Petite Terre 



Marie Galante 



10 15 km. 



22 - 33 



33 - 43 



30 - 38 



32 - 50 



30 - 42 



36 - 48 



m 38-53 
Figure 2. Geographic variation in number of dorsal scales contained in 
the standard distance at niidbody. The major islands and island p;ronps arc 
here named for future reference. 



liAZELL : GUADELOUP^EN ANGLES 



369 



pai'allcl to that line. In each case the average for all tlie speci- 
mens counted ^vas not more than ± 1 from the mean of the 
range given. Making the count in the manner outlined renders 
what might have been a most laborious sort of character as 
simple as possible, and yet shows (juite well the difpcrences noted 
between forms. (See Figure 2.) 





5 10 15 km, 
-I 1 , 



20 - 26 
22 - 28 



m 25-30 
Figui-e 3. Geographic variation in number of sulxligital lamellae under 
second and third phalanges of fourth toe. The major islands and islan<l 
groups are named in Figure 2. 



370 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

2. Suhdigital lamellae: Lamellae were counted under the sec- 
ond and third phalanges of the fourth toe. The differences are 
averages, and not diagnostic, but the geographic variation with 
respect to this character has been mapped because the variation 
is real and concordant with the variation in other characters. 
(See Figure 3.) 

SYSTEMATIC DISCUSSION 

Underwood recognized tive named populations and one un- 
named one as representatives of five distinct species, one with two 
subspecies; Williams would have added a sixth. In the present 
review all of those names regarded as valid by Underwood are 
retained, the Desirade anole he felt he could not properly name 
is described, and AVilliams' seventh form is accepted and de- 
scribed. I have, however, lowered all of them to subspecific rank 
under the same species. So that I may not immediately be 
scorned as a rabid lumper, let me point out that I have likewise 
described five more subspecies of the same species, making in 
all twelve subspecies. 

Anolis marnwratus Dumeril and Bibron, 1837, is the oldest 
available name for a Guadeloupeen anole. A. marmoratns may 
be distinguished from the adjacent forms by the following brief, 
species-level diagnoses : 

Anolis oculatus, of Dominica, is an anole of the Mmaculatus 
group, sensu Underwood, in which the prenasal scale borders on 
the rostral anteriorly and the anterior edge of a large nasal scale 
(entirely containing the naris) posteriorly; the prenasal is 
roughly quadrangular in shape. The ventrals are always at least 
faintly keeled, and the keels form lines that converge on the 
ventral midline posteriorly. 

Anolis marmoratus, of the Guadeloupeen archipelago, is an 
anole of the himaculatus group, sensii Underwood, in which the 
prenasal scale borders the rostral directly, extends posteriorly 
to or beyond the level of the anterior edge of the naris, and either 
borders the anterodorsal edge of the nasal, or itself forms the 
anterodorsal border of the naris. The ventrals may or may not 
be keeled, but if keeled at all the keels form lines converging 
towards (rarely ever reaching) the ventral midline, or parallel 
to it. 

Anolis livldus, of Montserrat, is an anole of the himaculatus 
group, sensu Underwood, in which the prenasal scale borders 
directly on the rostral, extends posteriorly to or beyond the level 



LAZELL : GUADELOUP^EN ANGLES 



371 





1 2 

Figure 4. Snout squamation in two species of Anolis: 1. A. marmoratus 
(MCZ 71202) ; 2. A. oculatus (MCZ (50364). The prenasal scale is shaded. 





Figure 5. Ventral keeling in two species of Anolis: 1. A. lividus (MCZ 
6176) ; 2. A. marmoratus (MCZ 71202). In A. marmoratus the ventrals may 

be entirely smooth. 



372 



BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



of the anterior edge of the naris, and either borders on the 
anterodorsal edge of the nasal, or forms the anterodorsal border 
of the naris itself — as in A. marmoratus. The ventrals are 
always at least faintly keeled, and while many lines of keels 
may converge on the ventral midline posteriorly, at least some, 
in the abdominal area, form lines which diverge. 








D 


mdrmoratas 


A 


inorndfus 


o 


d/Z/diceuS 


V 


desird^dei 


• 


girdfus 


c 


chrcjsops 


+ 


sefo3us 


F 


ferreus 


K 


Kdhoudnnensis 


X 


ferrdie<3i/{cxe 


A 


speciosus 


O 


Cd.ryd.e 



Figure G. Tlici ranges of the twelve forms of AnoUs maniioial us in tlie 
Giuuleloupeen areliipelago. The major islands and island groups are named 
in Figure 2. 



LAZKLL : GUADELOUI'KEN ANGLES 373 

Figure 4 show.s both coiulilioiis of tlic prenasal sealos, and 
Fi<;ure 5 shows examples of the most eonfiising sorts of abdominal 
keeling. Using these characteristics, the three species may be 
separated without too much difficulty, regardless of age or sex. 
I have seen some specimens in whicli the prenasal was equivocal 
on one side, but it was always definitely one sort or the other 
on the other side, and provided the correct identification. 

The ranges of the twelve forms recognized are mapped in 
Figure 6. 

The nominate form of the GuadeloupecMi species is : 

AxoLis iSJARMORATUS MARMOKATUS Dumeril and Bibron 
Anolis marmoratus Dumeril and Bibron, 1837, Erp. Gen. 4: 139. 

Holotype: Museum National d'Histoire Naturelle Ig. 43, no 
date, coll. Plee. 

Type locality: "Martiniciue" (in error) ; herein revised to 
Capesterre, La Guadeloupe. 

Diagnosis: Dorsal scales in the standard distance 36 to 48 
(average 42) ; 25 to 30 (average 28) subdigital lamellae; adult 
male green, changing to brown ; snout suffused with orange ; head, 
neck, and orbital area boldly marbled with bright orange ; throat 
fan light orange-yellow with yellow scales. Adult female green, 
with an obsolete middorsal pattern. 

Description: MCZ 71202 is noted in my field catalogue as 
"the most beautiful anole I have ever seen." In life, this adult 
male was bright apple-green, shading to blue on the tail and 
yellow-green on the limbs. No flank stripe was present. On 
the neck and head the ground color shaded to blue-grey ; the 
snout and head were broadly suffused with russet becoming 
in the temporal, orbital, and nape regions brilliant orange mar- 
bles, tending towards longitudinal stripes. The belly was lime- 
green. The throat fan was bright, pale orange-yellow with 
butter-yellow scales. In the dark phase the specimen assumed 
a deep chocolate-brown dorsally, became much darker ventrally 
• — even to the extent of darkening the throat fan — but retained 
the orange marbling. Aside from the marbling on the head 
and neck, there were no markings. This specimen, the largest 
examined, w^as 77 mm in snout-vent length. 

The adult female is grass-green, shading to grey or grey- 
brown on the head, middorsum, and tail, and with a lime-green 
belly. Aside from the contrast between the green of the sides 



374 BULLETIN : MLTSEUM OF COMPARATIVE ZOOLOGY 

and the grey to grey-brown of the middorsnm, producing the 
pattern I have termed "obsolete," there are no markings in 
life. Color change is merely from darker to lighter. 

Variation: The extent of marbling varies in the adult male 
from all over the head and neck, to or beyond the level of the 
shoulder (as in the holotype), to restriction to the head region 
only. The sutfnsion of orange pigment anterior to the eyes, 
however, is constant in all, and the lack of it will serve to dis- 
tinguish intergrades with other forms which may also show 
orange marbling. The ground color of the head varies from 
slatey blue-gre^' to powder blue-grey. 

Distrihution : This form is restricted to the plain of Capes- 
terre, southwestern La Guadeloupe. 

Specimens examined: MCZ 56043, "Guadeloupe" (Guesde 
coll.); MCZ 71179-93, Capesterre ; MCZ 71194-201, Bananier; 
MCZ 71202-12, Routhiers; MCZ 71213-22, Caraiigaise. 

Discussion: This spectacular anole has very narrow areas of 
intergradation to the west and south with the montane form 
and intermediates between the montane form and the southern 
leeward coast form. To the north, however, there is little barrier 
or ecological break, and a lengthy zone of intergradation with 
speciosus extends along the coast. MCZ 71140-43, from Grande 
Etang, ca. 400 meters elevation, are intergrades with alliaceiis, 
the montane form. MCZ 71150-61 from Dole, MCZ 71172-78 
from Morne-a-Zailes, and MCZ 71162-71 from Trois-Rivieres re- 
present three-way intergrades between niarmoratus, alUaceus, 
and the southern leeward coast form, girafus. MCZ 71136-39 
from Ste. Marie, MCZ 71128-35 from Goyave, and MCZ 71113-27 
from Petite Bourg represent intergrades with speciosus, which 
occupies the "waist" between La Guadeloupe and Grande Terre 
as well as southwestern Grande Terre. 

Anolis mabmoratits alliaceus Cope 

Anolis alliaceus Cope, 1864, Proc. Acad. Nat. Sei. Philadelphia, 175. Type: 
British Museum of Natural History (BMNH) 946. 8.28.96, no collector, 
no date. 

Anolis bimaciilatus alliaceus, Underwood, 1959, p. 199. 

Type locality: None designated; here restricted to Maison 
Forestier du Matouba, elevation 700 meters. La Guadeloupe. 

Diagnosis: Dorsals in the standard distance 36 to 48 (average 
42); 25 to 30 (average 28) subdigital lamellae; adult male 
green with no blue or bluish ]iigmeiit in this ground color; 



LAZKLIj : GUADELOUPEEN ANGLES 



375 



|)alp('l)fal area of ()rl)i1 white in tlie liLilit |)liase, chaii^niijj: to 
grey as the animal turns dark green ; dark dots, tending to run 
together, scattered over the anterior and dorsal surfaces, and 
set off by pale cream borders; thi-oat fan deep orange with 
green scales. Adult female green with mottled middorsal ])at- 
tern and small light or dark dots anteriorly. 

Description: An adult male, MCZ 71340, from the type lo- 
cality, was pea-green and completely lacked the bluish tones 
apparent on the posterior body or tail in males of all other forms 
from La Guadeloupe. The orliital area was brown-green, but 
the edges of the lids (palpebral area) were white. Large blue- 
black dots, some running together to form short marbling, were 
present dorsally; these dots were set off by cream-yellow areas 
that blended abru])tly into the pea-green ground color. A vague, 
cream-yellow flank stripe was indicated across the forelimb in- 
sertion. Dull yellowish green on the temporal region extended 
posteriorly to beyond the ear, and was set off by a dark brownish 
streak along the upper mandible and a similar streak through 
the eye. The throat fan was dark, dull orange with yellowish 
green scales. The belly was bright green. Color change involved 
a darkening of the ground color, obscuring the head streaking, 
but intensifying the contrast between the ground color and the 
cream-yellow borders of the dots. This specimen, the largest 
examined, measured 72 mm snout to vent. (See Figure 7.) 




Figure 7. A representative pattern in adult male Anolis marmoratiis al- 
liaceus (MCZ 71340). 



The adult female, in life, is duller green than the male, and 
shows a middorsal pattern of light and dark mottlings. Spots, 
small and sometimes indistinct, of dark or light pigment arc 
present on the anterior trunk. The head streaking is usually 
present and notable. 



376 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Variation : The extent of dotting is extremely variable ; some 
specimens are dotted and marbled extensively over the posterior 
nape, the shoulders and anterior middorsum ; other specimens 
show only one indistinct dot in the region of the axilla. In some 
specimens the head streaking is indistinct. The complete lack 
of blue in the ground color, and the throat fan color combination, 
suffice to distinguish this form invariably from other green 
marmoratus even should a completely dotless specimen be en- 
countered. The characters noted, as well as the bright green 
belly, serve to distinguish this form from the only other spotted 
anole on La Guadeloupe, the southern leeward coast form girafus. 
There is little variation in females. 

Distribution: This form is restricted to rain forest in the 
central highlands of La Guadeloupe. It is strikingly arboreal 
and therefore difficult to collect, especially in climax forest, 
where the trees may reach 40 meters in height. None were seen 
at elevations higher than 900 meters. 

Specimens examined: MCZ 61078-81, Matouba, 2000 ft. (= ca. 
600m), nr. St. Claude (Proctor coll.) ; MCZ 71338-46, Maison 
Forestier du Matouba, 700 meters; MCZ 71347-55, Trace Victor 
Hughes, between Matouba and Grande Decouverte, ca. 850 me- 
ters ; MCZ 71356, Etang-as-de-Pique ; MCZ 71358-60, north ridge, 
Morne Moustique, ca. 650 meters. MCZ 71357, from Morne Goton, 
ca. 650 meters, has somewhat elongate dorsal scales, reminiscent 
of the north coast form, setosus. It is otherwise typical of 
alliaceus; Morne Goton is therefore taken to be the northern 
limit of the range of alliaceus. 

Discussion: Intergradation with the nominate form has been 
discussed under that form. The montane anole, alliaceus, inter- 
grades with speciosus between the ' ' waist ' ' and the central high- 
lands at Vernou (MCZ 71144-49). Intergrades with setosus of 
the north coast are represented by MCZ 70883-4. from Sofaia, 
ca. 400 meters. Intergradation with the southern leeward coast 
form, girafus, is extensive and has caused the greatest confusion 
possible. This has been true because both are spotted forms, 
and the zone of intergradation includes both the towns of Basse- 
Terre (MCZ 71231-44) and Ste. Claude (MCZ 71287-303) — 
the two largest settlements on the island of La Guadeloupe. 
Evidence of alliaceus influence is present at sea level east of 
Basse Terre: MCZ 71223-48, from Delgres, and MCZ 71245-58, 
from Vieux Fort are intermediate series. This interesting re- 
gion, where montane influence extends right to the coast, will 



LAZELL : GUADELOUPEEN ANGLES 377 

be considered under "Evolutionary Discussion." Typically, the 
intermediates sliow a pattern closely ai)proacliin<; ulliaceus and 
coloration similar to girafus. Underwood's description of BMNII 
1946.8.28.96, the holotype, does uot rule out the possibility that 
this specimen may have come fr-om this intermediate, southern 
tip i)opulation. Assignment of the name alliaceus to the mon- 
tane form is, therefore, arbitrary, but supported by the de- 
scribed resemblance of the holotype 's pattern to that of the 
montane form (the holotype 's coloration in life is, of course, not 
available for discussion). In reality, these two forms are not 
confusingly similar, even in preservative, but very careful at- 
tention must be paid to their diagnostic characteristics if con- 
fusion, due to the spotted pattern generally present in both, 
is to be avoided. This is an example of a case where obvious, bold 
markings can be more confusing than useful simply because 
they are variably present in both forms, whereas more subtle 
characters can always be relied upon to be consistent and defini- 
tive. 

Anolis marmoratus girafus^ subsp. no v. 

Holotype: MCZ 71259, collected 14 August 1961 by J. D. 
Lazell, Jr. 

Tyjje locality: Vieux Habitants, La Guadeloupe. 

Diagnosis: Dorsals in the standard distance 38 to 53 (average 
47) ; 25 to 30 (average 28) subdigital lamellae; adult male blue- 
green to brown, always browner on the head and neck and always 
at least bluish on the posterior body and tail base ; pale streaks 
and stipples, usually running together to form stripes that pro- 
duce a reticulate pattern isolating dark spots, on the lateral 
trunk; throat fan pumpkin yellow with cream-colored to white 
scales. Adult female pale grey-brown with broken middorsal 
pattern. 

Description of holotype: This adult male was warm brown on 
the head and neck, somewhat mottled wdth darker grey-brown. 
Posteriorly the ground color was pale blue-green, becoming bluer 
on the base of the tail. On the sides of the neck, in the axillary 
region, and along the low^er costal region were dark grey-brown, 
polygonal spots separated by a pattern of broad, pale, cream 
to bluish reticulations which blended with the posterior ground 



1 The uauie girafus has beeu iuveuted to indicate the reticulate pattern. 



378 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

color. The belly was dirty white. The throat fan was bright 
pumpkin yellow with white scales. (See Figure 8.) 

Variation: This is the most variable form on La Guadeloupe. 
As with A. 0. cahritensis on Dominica (see Lazell, 1962, p. 470), 
there is some correlation of variation and geography. In the 
southern part of the range specimens are often quite bright 
blue-green and have a well developed pattern of reticulations 
that sometimes leave only a few, well-isolated dark dots in the 
axillary region. In the northern part of the range many speci- 
mens have merely several series of light spots along the sides 
which, though they coalesce, fail to produce a very reticulated 
pattern; northern specimens are also rather bright greenish. 
In the central portion of the range there is a dilution of green 
to the point where often only a faint blue tinge remains on the 
posterior body and tail base of an otherwise dingy grey-brown 
anole ; too, in the central part of the range, the entire animal 
may be so dingy that the light spots and reticulations only show 
up in strong contrast when the animal is in the dark phase. 
There are no sharp breaks in this variation, and, in fact, speci- 
mens that approach all of the described variations can be col- 
lected in any part of the range. Therefore, though there are 
average differences in color pattern, the clinality and incon- 
sistency of this variation precludes dividing this form up into 
a number of races with smaller ranges. All specimens from all 
parts of the range fit the diagnosis given for the subspecies. 
Some pattern variants are shown in Figure 8. 

The adult females vary from fawn-brown to ash-grey, and 
have a paler middorsal stripe set off by coalescing dark spots. 
This produces what I have called the "broken" middorsal 
pattern. 

Distribution: A. m. girafus occurs along the leeward coast of 
La Guadeloupe from just northwest of Basse-Terre to Malen- 
dure. This is the driest region on La Guadeloupe, and perhaps 
in the entire archipelago. It corresponds, as has been pointed out, 
with the northern leeward coast of Dominica. Convergence 
between the anoles occupying these two areas will be considered 
under "Evolutionary Discussion." 

Paratijpes: MCZ 71260-77, same data as the type; MCZ 71278- 
86, Baillif; MCZ 71304-18, Marigot ; MCZ 71319-28, Boulliante; 
MCZ 71329-37, Malendure. 

Discussion: Intergradation with alliaccus has been discussed 
under that form. A. m. girafus also intergrades with the north 



LAZELL : GUADELOUPEEN ANGLES 



379 






Figure 8. Pattern variation in adult male Anolis mannoratus girafus. 
1. MCZ 71529, the type; 2. MCZ 71331; 3. MCZ 71304. 



380 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

coast form, setosus, at the following localities : Anse Caraibe : 
MCZ 70850-58; Pointe Noire: MCZ 70841-49; Trou-Caverne : 
MCZ 70859-68; Ferry: MCZ 70869-82. These intergrades tend 
to extremes : from any one locality within the zone of intergra- 
dation one may collect specimens that closely resemble either 
girafus or setosus, though the majority show a variable combina- 
tion of diaracteristics. 

Anolis marmoratus setosus^ subsp. nov. 

Holotype: MCZ 70813, collected 11 August 1961 by J. D. Lazell, 
Jr. 

Type locality : Pointe Allegre, La Guadeloupe. 

Diagnosis : Dorsals in the standard distance 38 to 53 (average 
47); 22 to 28 (average 25) subdigital lamellae; dorsal scales 
spinose, those of the nape region so much taller than broad that 
a distinctly furred effect is produced ; adult male blue-green 
with sooty transver.se markings and a dark stripe through eye 
indicated when changing to the dark phase ; throat fan yellow 
with greenish scales; belly pale, but without yellow tint. Adult 
female without a middorsal pattern as such, but wath a variega- 
tion of green, brown, slate, and white speckles and blotches on 
dorsum, and bold, dark streaks on the lateral venter. 

Description of holotype: This adult male was a nondescript 
green lizard immediately distinctive only because of the most 
peculiar character of the squamation. The dorsal ground color 
was green, shading to blue-green posteriorly and with some 
bluish wash on the head. The sooty transverse markings were 
not apparent except when changing from the light to the dark 
phase, or vice versa. The stripe through the eye was, however, 
noticeable in any phase. The belly was pale green ; the throat 
fan was bright yellow with greenish or grey-green scales. Color 
change was to much darker, rendering the specimen almost black 
dorsally, and obliterating the dorsal markings — which, though 
diagnostic, seem to be never more than temporary. The type 
had several clusters of one to six bright yellow scales on the 
neck in no particular arrangement. The squamation is the most 
distinctive feature. It is, nevertheless, difficult to describe. The 
dorsals are conical to the point of being spines; this condition 
is accentuated in the nape region, and quite literally gives the 



1 Setosus, liatin, for "bristly." 



LAZKLL : (ilADKr.OUPfiEN ANGLES 381 

most fuiTcd effect iiuatiiiialile on an aiiole (see Figure 9). The 
liolotype, the largest speciineii examined, measured 6G mm snout 
to vent. 

Variation: The diaynostie eolor pattern and squamation are 
quite consistent, but the amount of Ijlue varies from the eondition 
deseribed for the liok)type to a general blue wash. The peculiar 
clusters of yellow "spines" (scales) on the neck appear only 
in occasional adult males and are not relevant to the taxon. 

The adult female is variable but always variegated and lacks a 
genuine middorsal pattern. The ground color is blotchy green, 
and brown, slate-grey, and pale grey or white mottles and 
blotches are present. There are bold, dark series of stipples 
forming streaks along the sides of the otherwise dirty white 
venter. 

Distribution: This form is confined to the northern coast of 
La Guadeloupe. 

Paratijpes: MCZ 70814-19, same data as the type; MCZ 
10403-27, Ste. Rose (Noble coll.); MCZ 70804-12, Ste. Rose; 
MCZ 70820-32, Deshaies; MCZ 70833-40, Rifflet. 

Disci(ssio)t: It was specimens of this form, plus intergrades 
between alliaceiis {sensu Lazell) and girafus, that constituted 
Underwood's concept of alliaceus. As Underwood noted, Wil- 
liams regarded the Ste. Rose series a.s distinct. Williams (pers. 
comm.) was on the verge of describing the Ste. Rose series as 
a distinct species because of the remarkable squamation when 
the first shipment of my anoles from the Guadeloupe region 
arrived ; this shipment contained intergrades between sctosus 
and speciosus, as well as the other two forms setosus touches 
on. Credit for its most apt and descriptive name, however, re- 
mains with Ernest E. Williams. 

Intergradation with alliaceus and girafus has been discussed 
under those forms, respectively. Intergrades between sctosus 
and speciosus occur along the extreme northeast coast of La 
Guadeloupe between Lamentin (MCZ 70988-96) and ]\loi-ne 
Rouge (du Nord) (MCZ 70997-1003). 

The population on Uet-a-Fajou, intermediate generally be- 
tween setosus and speciosus, requires discussion separately. 
MCZ 71004-13 from Ilet-a-Fajou fit the diagnostic color charac- 
ters of speciosus (see diagnosis of that form) quite closely. I 
would have included them, therefore, under this form except 
that E. E. Williams pointed out the rather spinose character 
of their squamation. The combination of setosiis-type squama- 
tion and speciosus-tyi)e coloration and pattern is common in 



382 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

mainland intergrades between these two forms, and it is quite 
plausible to speculate that the Ilet-a-Fajou population was de- 
rived from a few specimens, from the adjacent coast, which had 
this combination ; this might explain its consistency in Ilet-a- 
Fajou anoles. A careful examination of these anoles, however, 
revealed another interesting fact : they possess rather large 
scales — there being only 33 to 43 (average 37) contained in 
the standard distance. Since the character is not diagnostic, 
it fails to differentiate this population as a taxon, but indicates 
that a trend towards abnormally large scales may be expected 
in Anolis marmoratus populations confined to very small islands. 
I have tentatively assumed that this characteristic can, in fact, 
be expected, and on that entirely shaky foundation classify the 
following form as : 

Anolis marmoratus kahouannensis subsp. nov. 

Holotypc: MCZ 70791, collected 28 August 1961 by J. D. 
Lazell, Jr. 

Type locality: Ilet-a-Kahouaiine, Guadeloupe Passage, NW of 
La Guadeloupe. 

Diagnosis: Dorsals in the standard distance 30 to 38 (average 
33); 22 to 28 (average 25) subdigital lamellae; dorsal scales 
conical, producing a bulldog-collar-spike effect on the nape ; 
adult male chartreuse (= bright yellow-green) with no mark- 
ings except bluish washes on the head and chin ; belly bright 
yellow^ ; throat fan bright yellow with yellow scales. Adult 
female chartreuse with a bright yellow belly and no markings 
except occasional traces of a ladder middorsal pattern. 

Description of Jiolotype: In my field catalogue I have de- 
scribed this adult male as "a solid, brilliant chartreuse anole. 
Changes to dark green but never has any markings." There 
was a bluish wash on the snout and temporal region which con- 
tinued onto the chin and anterior edge of the throat fan. The 
throat fan was pumpkin-yellow with bright yellow scales. The 
belly was butter-yellow. The orbital region was pale. Color 
change, as noted, was merely to darker. The scales are extremely 
large, and the difference between them and the scales of main- 
land anoles may be readily noticed in the field. Combined with 
their large size is the setosus-\ike characteristic of spinosity 
(though not to nearly so great an extent) ; the effect of conical, 
spike-like dorsal scales, especially on the nape, is striking (see 
Figure 9). The holotype, the largest specimen examined, meas- 
ured 7G mm snout to vent. 



LAZELL : GMAOELOUPl^EN ANGLES 



383 



>:^ 







Figure 9. Nape scales just lateral to the dorsal midline in two forms of 
Anolis marmoratus: 1. kahouannensis, type (MCZ 70791); 2. setosus, type 
(MCZ 70813). 



Variation: The extent of blue wash on the heads of males 
varies from the condition described for the holotype to virtually 
absent. One specimen (MC'Z 70792) darkened in blotches when 
changing- to the dark phase; this was only vaguely reminiscent 
of the condition visible in setosus. 

The adult female is almost completely without markings. There 
i.s no mottling, stippling, or streaking, though occasional seg- 
ments of the ladder middorsal pattern characteristic of the 
young female may be retained in sexually mature individuals. 
The basic color is pea-green, and the belly is bright yellow. 

Distribution: This anole is confined to Ilet-a-Kahoiianne. 

Paratypes: MCZ 70792-803, same data as the type. 

Discussion: Assignment to subspecific rank under mnrmoratus 
is, in this case, an arbitrary action supported only by direct 
evidence, in the Ilet-a-Fajou population, that a tendency towards 
large scale size can occur in small, isolated marmoratus popula- 
tions. Because the Ilet-a-Fajou population does demon.strate that 
enlarged scale size is within tli(> potential evolutionary role of 



384 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

marmoratus, it is at least possible to regard kahouannetisis 
as a subspecies of marmoraius with respect to this character. 

It is, however, disquieting to note that kaJiouannensis is 100 
per cent distinct on the basis of coloration in life, quite apart 
from the scale size discrepancy. In the final analysis, there is 
no conclusive argument for the inclusion of this form within 
the marmoratus species; there is, nevertheless, a tenable argu- 
ment that it should be included, since all of the mainland 
Guadeloupeen forms are 100 per cent distinct on the basis of 
coloration in life if intergrades are not considered. A. m. ha- 
houannensis has no possibility of producing an intermediate 
population with the mainland forms, but I have, nevertheless, 
accepted it as a subspecies of marmoratus because such a judg- 
ment is tenable and because in my own opinion kaJiouannensis 
is not more distantly related to setosus than setosus is to those 
mainland forms with which it intergrades directly. My opinion 
is based on a general impression of these taxa both in life and 
after preservation ; it is thus the sort of opinion that can neither 
be proven nor disproven on the basis of present information. 
Authors who wish to regard this form as a species distinct from 
marmoratus can find ample justification for doing so. However, 
the Kahouanne Island anole resembles setosus with regard to 
the convexity and spinosity of the dorsal scales, and fits A. 
marmoratus generally with regard to the prenasal and the ventral 
keeling. 

Anolis MARMORATUS sPECiosus Garmaii 

Anolis speciosus Garman, 1887, Bull. Essex Inst., 19:45. Cotypes: MCZ 

6172, 70947-50. 

Lectotype: Here designated as MCZ 6172, collected by Richard- 
son, March, 1886. 

Type locality: "Marie Galante" (in error) ; here revised to 
Pointe-a-Pitre, Grande Terre. 

Diag7iosis: Dorsals in the standard distance 32 to 50 (average 
40); 20 to 26 (average 23) subdigital lamellae; adult male 
green, without dorsal markings ; venter brightly washed with 
yellow ; orbital area sky-blue ; throat fan sulfur-yellow with 
greenish scales. Adult female olive with ladder or striped mid- 
dorsal pattern. 

Description: MCZ 70961, an adult male from Pointe-a-Pitre, 
in life was bright green over the entirely unmarked dorsum. 



LAZELL : GUADELOUP^EN ANGLES 385 

The venter was entirely washed with bright yellow, producing 
a deep yellow-green zone along the sides. The orbital skin was 
skA'-blue, and sharply set oflP from the green color of the rest 
of the head. The throat fan was sulfur-yellow with green-grey 
scales. This male had several clusters of yellow scales scattered 
on the sides of the neck, reminiscent of some sctosiis males. The 
scales of the dorsum are not spinose (i.e. never taller than 
broad), and closely resemble the dorsal scales of anoles (exclud- 
ing setosus) from La Guadeloupe. Color change involved merely 
a darkening of the ground color to slatey-green, accompanied 
by greying of the orbital skin. This specimen, the largest exam- 
ined, measured 71 mm in snout-vent length. 

The adult female is olive-green, has a striped or ladder mid- 
dorsal pattern, and lacks other distinctive markings including 
a flank stripe. 

Variation: This form is remarkably constant in color charac- 
ters. As with setosus, the presence of yellow scale clusters on 
the neck is occasional in old adult males and not relevant to the 
taxon. Specimens from Ilet-a-Cochons and the south coast of 
Grande Terre sometimes show a more gradual blending of the 
blue coloration of the orbital region with the green of the head 
than do specimens from the more northern portions of the 
range. There is, however, never a dark stripe through the eye, 
as in setosus. 

Distribution : This form occurs throughout SW Grande Terre 
(i.e., the wetter area of this island), on the "waist" between 
Grande Terre and La Guadeloupe, and on Ilet-a-Cochons (some- 
times called, uncomplimentarily enough, Ilet-a-Gouvernement). 

Specimens examined: MCZ 6172, "Marie Galante," Lectotype 
(Richardson coll.) ; MCZ 70947-50, "Marie Galante," Paralecto- 
types (Richardson coll.); MCZ 70913-24, Abymes; MCZ 70925- 
34, Gosier; MCZ 70935-46, Ste. Anne; MCZ 70951-60, Baie 
Mahault; MCZ 70961-77, Pointe-a-Pitre ; MCZ 70978-87, llet-a- 
Cochons, ou Gouvernement. 

Discussion: The locality of this form given by Garman (pre- 
sumably fide Richardson) in the original descrii)tion is incorrect. 
The five males in the type series (MCZ 6172, 70947-50) fit quite 
precisely with the form from SW Grande Terre on squamation 
characters and are powder-blue from long preservation. They 
completely lack markings such as the faint flank stripe and 
brown head (which does not turn blue in preservative) that 
characterize the NE Grande Terre population, the only other 
form that these long-preserved specimens might conceivably be 



386 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

confused with. Richardson demonstrably collected in both De.si- 
rade and Marie Galante. It would have been remarkable indeed 
if he had failed to stop at the large and busy port of Pointe-a- 
Pitre while in this area. To add to the evidence against the 
"Marie Galante" locality is the fact that no specimen resembling 
speciosus has ever been collected there since, whereas the Marie 
Galante anole, ferreus, is common indeed — though its original 
type locality was cited as "Guadeloupe." 

Intergradation with nominate marmorafus, oUiaceus, and seto- 
sus ha.s been discussed under those forms, respectively. Inter- 
gradation with the dry country form of NE Grande Terre, 
inornatus, occurs along a line through Morne-a-L'Eau (MCZ 
70885-94), Chateau Gaillard (MCZ 70895-902), and St. Francois 
(MCZ 70903-12). 

Anolis marmoratus inornatus^ subsp. nov. 

Holotype: MCZ 71036, collected 13 August 1961, by J. D. 
Lazell, Jr. 

Type locality: Anse Bertrand, Grande Terre. 

Diagnosis: Dorsals in the standard distance 38 to 53 (average 
47) ; 20 to 26 (average 25) subdigital lamellae; adult male pale 
grey -green on trunk, rich brown on head ; orbital area brown ; 
belly pale lime-green; throat fan yellow with white to cream- 
colored scales ; flank stripe indicated. Adult female pale grey- 
brown with striped middorsal pattern and flank stripe. 

Description of holotype: This adult male was pale green 
with a bluish tinge on the posterior body and tail base. The 
head was Avarm brown ; the orbital skin golden brown. The 
brown of the head graded gradually into the green of the dorsum. 
There were faint, grey-brown vermiculations on the nape. The 
belly was pale, dirty green posteriorly, becoming lime-green in 
the chest region. The throat fan was dull yellow with white 
scales. A flank stripe, paler grey-green than the dorsal ground 
color, extended from the shoulder to the hind limb insertion. 
There were faint indications of darker grey-brown transverse 
markings across the dorsum. The slight color change involved a 
general trend towards becoming darker and browner. This speci- 
men, the largest examined, measured 75 mm snout to vent. 

Variation: This form is rather variable. Some specimens lack 
all signs of neck vermiculations or transverse markings. The 

1 hiornatun, Latin, for "unadorned." 



LAZELL : GrADETiOrPKEN' ANOLES 387 

amount of green varies from tlic condition described for the 
li()loty])e to one in whicli it is virtually restricted to tlie posterior 
belly and rump regions. In most specimens the throat fan ap- 
pears to have a paler yellow border and a brighter yellow center, 
and the scales of the fan are often closer to cream-color than 
white. The variation is individual and does not correspond to 
different localities within the range of the form. 

The adult female is pale tan to ash-grey on the dorsum, and 
always brownish on the head. The striped middorsal pattern 
is not bold but is always noticeable. A definite flank stripe is 
indicated in the thoracic region. 

Distribiitton: This form occurs throughout northern (4rande 
Terre and extends southeastward along the northeast coast of 
that island towards, but not to, Pointe-des-Chateaux. 

Parotjjpes: MCZ 71037-42, .same data as the type: :\1C'Z 61082- 
92, Mouie (Proctor coll.) : MCZ 71014-19, Moule ; MCZ 71020-25, 
Petite Canal: MCZ 71026-35, Port Louis; MCZ 71043-48, Cam- 
peche; MCZ 71049-57, town of Ste. Marguerite. 

Discusfiion: Intergradation with spcciosna has been discussed 
under that form. The population on the Pointe-des-Chateaux 
peninsula requires especial consideration. The males from this 
area show definite vermiculation on the nape, and usually a 
few bold, dark spots at least in the dark phase. There is a 
noticeable yellow wash along the sides and the orbital skin has 
a distinctly orangish tone in some specimens. In keeping with 
the norm of intergrade populations in the archipelago, the.se 
anoles are very variable : some closely resemble inornatus in 
important respects, others closely approach the anole found 
on the adjacent island of La Desirade. Therefore, MCZ 71058-67, 
from Pointe-des-Chateaux, are regarded as a sample of an inter- 
mediate population between inornatus and the following form : 

Anolis marmoratus desiradei subsp. nov. 

Holotype: MCZ 71068, collected 14 September 1961. by J. D. 
Lazell, Jr. 

Type locality: Grande Anse, La Desirade. 

Diagnosis: Dorsals in the standard distance 32 to 50 (average 
40) ; 22 to 28 (average 25) subdigital lamellae; adult male pale 
greenish with yellow wash on sides and yellow belly ; dorsal 
surfaces extensively vermiculated wath darker grey -brown ; throat 
fan yellow with white to cream-colored scales; orbital area bright 



388 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 

rust-red ; chin yellow with bold blue-grey streaking. Adult fe- 
male grey-greenish with grey head and yellow belly; middorsal 
pattern obsolete. 

Description of holofype: This adult male was pale grey-green 
boldly vermiculated with dark grey-brown all over the dorsal 
surfaces of the trunk and legs. The lateral surfaces were washed 
with yellow, and the belly was bright yellow. A lack of vermicu- 
lation along the side indicated a vague flank stripe. The chin 
was yellow and blue-grey bars ran from the anterior base of 
the throat fan to the infralabials. The head was dull brown to 
grey-brown, and the bright rust-red of the orbital skin stood 
out in bold contrast. The throat fan was yellow with cream- 
colored scales. Color change involved general darkening and 
increased brownness ; the vermiculations became especially bold 
in the dark phase. The holotype, the largest specimen examined, 
measured 80 mm snout to vent. 

Variation: There is a definite cline in extent of yellow on the 
sides and in the ground color, increasing as one proceeds east- 
ward along La Desirade. Some specimens from all over the 
island show small orangish patches on the nape and anterior 
body; this is by no means constant and not characteristic of 
the taxon. 

The adult female is distinctly grey on the head and becomes 
greener posteriorly. There is no indication of vermiculation. 
The belly is distinctly yellow. Young specimens show a vague 
striped middorsal pattern, but those apparently mature females 
were somber grey middorsally, producing the pattern I have 
called obsolete. 

Distribution: This form is confined to the island of La Desi- 
rade. 

Paratxjpes: MCZ 57285-96, "Desirade Id." (Richardson coll.) ; 
MCZ 62210-1, Ravine la Riviere (Proctor coll.); MCZ 62212, 
Le Calvaire (Proctor coll.) ; MCZ 62213-17, Grande Anse (Proc- 
tor coll.) ; MCZ 71069-77, Grande Anse; MCZ 71078-87, Pointe- 
des-Colibris; MCZ 71088-100, Le Souffleur; MCZ 71101-12, Pointe 
Double. 

Discussion: The intermediate population between inornatiis 
and desiradei has been discussed under that form. It need only 
be pointed out here that this population, while not one of 
"intergrades" as such, precludes the possibility of recognizing 
desiradei as a species distinct from marmoratus: on Pointe-des- 
Chateaux, Grande Terre, some anoles that are unequivocally 
marmoratus show desiradei characteristics. 



LAZELL : GUADELOUPEEN ANGLES 389 

lj('<i'iiiiiin^- with dcsirdih i \hevv is a stcppcd-cliiic sci-ics throu<>:h 
tlic "satellite" islands of the ardiipchiiio. Tlic first pojjulation 
of this series is : 

AxoLis MAR:\iOKATrs ciiRVsops^ sn])sp. IIOV. 

Ilolohjpi : MCZ 7064!), collcc-tcd 4 September l!)(il, hy J. 1). 
Lazell, Jr. 

Ti)p( local ih/: Terre de Hant, T^es Ties de la Petite Teri-e. 

Diagnosis: Dorsals in the standard distance 30 to 42 (average 
36) ; 22 to 28 (average 25) subdigital lamellae; adult male som- 
ber green-grey with bright yellow suffusion on the sides and 
bright yellow belly; vermieulations present on the anterior 
trunk and nape, at least, and dark dotting usually present on 
remaining dorsal surfaces ; orbital area red-gold ; chin entirely 
blue-grey; throat fan yelloAv with pale yellow scales. Adult 
female grey with yellow belly, an ob.scure striped middorsal 
pattern, and a brief flank stripe. 

Description of holotype: This adult male was grey-green, 
becoming greener posteriorly and virtually grey (or grey-brown) 
on the head. The yellow of the venter extended as a bright 
suffusion over the lateral trunk. The vermieulations tended to 
break up into small speckles on the i)osterior body and hind 
limbs; no notable lack of vermiculation distinguished a flank 
stripe region. The chin was entirely blue-grey, and the skin of 
the orbital area was red-gold. Color change was merely to 
slightly darker and browner. The holotype, the largest specimen 
examined, measured 73 mm snout to vent. 

Variation: The extent of vermiculation and its break-up into 
speckling is rather variable, but specimens always show vermicu- 
lation as such at least on the nape and anterior trunk. Some 
specimens showed a vague indication of the vermiculation-free 
flank stripe area, though this region is usually heavily invaded 
with yellow. The color of the orbital skin and the uniformity of 
the blue-grey chin are constant features. 

The adult female is distinctly duller and greyer tlian the 
average desiradei female and retains the striped middorsal 
pattern. The contrast between the grey of the head and the 
green-grey of the dorsum is not marked, though the belly is 
bright yellow. A short flank stripe is present. 

Distribution: Terre de Haut and Terre de Bas, Les lies de la 
Petite Terre. 

1 Chrysos, Latiu, for "^olil," [ilits oijs, Gri'ok, tor •'iippeariiiu'e." 



390 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Paratypes: MCZ 70656-65, same data as the type; MCZ 
70650-5, Trou Canard, Terre de Bas, Les lies de la Petite Terre. 

Discussion: The Petite Terre anole agrees with desiradei in 
possessing vermiculations, though they are reduced from the 
condition in that form; it agrees, on the other hand, with 
ferreus in having a uniform blue-grey chin, though the blue- 
grey does not extend onto the throat fan, as it usually does 
in ferreus. The orbital skin color, though entirely distinctive, 
is what one would expect of a mixture between the rust-red of 
desiradei and the dull yellow of ferreus. The extent of yellow 
on the lateral surfaces is likewise intermediate between these 
two forms. Dorsal scale size shows a marked overlap with 
desiradei, on the one hand, and ferreus, on the other. Some 
adult males have the neural spines of the caudal vertebrae dis- 
tinctly more elongate than in any desiradei and as elongate as 
in some ferreus. Therefore, in every respect except maximum 
snout-vent length (in the sample available), chrijsops is morpho- 
logically intermediate between two extremes : desiradei and 
ferreus. 

In contrast with the Ilet-a-Fajou population, which is also an 
isolated morphological intermediate, cJirysops is entirely dis- 
tinctive in its own right ; there is no intergrade population 
with which chrysops individuals could be confused, and there 
are diagnostic characteristics by which chrysops may be un- 
equivocally distinguished. For these reasons A. m. chrysops 
is granted nomenclatural rank. Because it is an intermediate 
population between A. m. desiradei and ferreus of Marie Galante 
and because it is geographically intermediate as well, it connects 
the Marie Galante anole with the remainder of the marmoratns 
series, and ferreus must therefore be regarded not as a distinct 
species but as : 

Anolis marmoratus ferreus (Cope) 

XipJiosunts ferreus Cope, 1864, Proc. Acad. Nat. Sci. Philadelphia, 168. 

Type: BMNH 1946. 8.5.59., no collector, no date. 
Anolis asper Garman, 1887, Proc. Essex Inst., 19: 31. Syntypes: MCZ 6162. 

(Type locality Marie Galante.) 

Type locality: "Guadeloupe" (in error) ; here revised to 
Morne Constant, Marie Galante. 

Diagnosis: Dorsals in the standard distance 22 to 38 (average 
28); 25 to 30 (average 28) subdigital lamelhie; adult male 
somber grey-brown becoming greener posteriori}- ; dorsum sprin- 
kled with dark dots seldom coalescing to form short vermicula- 
tions ; suffusions, often forming blotches, of yellow laterally ; 



LAZELL: GUADELOUPfiEN ANGLES 391 

orbital area dull yellow; uiiifoiiii l)lue-<i:rey of eliiii ol'tcii invad- 
iiio- otherwise yellow throat fan with yellow scales. Adult 
female grey-brown to greenish with brief flank stripe, obsolete 
niiddorsal pattern, and a very pale yellowish belly. 

Description: An adult male from Moriie Constant was dingy 
grey-brown shading to brownish blue-gr-ecn on the tail and 
dull blue-grey on the head. The sides were suffused with rich 
yellow, forming large blotches anteriorly. The venter was duller, 
paler yellow. The chin wa^ entirely blue-grey, and this (!olor in- 
vaded the anterior ({uarter of the throat fan; the remainder of 
the Ihroat fan was bright yellow with yellow scales. The orbital 
region was dull yellow, strikingly distinct from the blue-grey 
of the snout, though less abruptly blending into the browner 
grey of the temporal region. The nape and dorsum were liberally 
speckled with dark grey-brown. This specimen, MCZ 70748, 
shows a remarkably high tail crest, and, in life, had three to 
five longitudinal chestnut-brown stripes along that crest. This 
specimen measured 99 mm snout to vent, though a specimen 
from Vieux Fort (the largest examined), MCZ 70767, measured 
119 mm snout to vent, thus 21 mm larger than the largest fer- 
reus previously recorded (Underwood, 1959, p. 203). 

The adult female is usually much greener than chrysops and 
always lacks the brightness of the yellow belly. Large specimens 
have the striped middorsal pattern reduced to obsolescence : a 
short flank stripe, in the shoulder region, is noticeable. 

Variation: The speckling ranges from the condition described 
above to but a few scattered stipples, covering one to four scales, 
in the nape region: thus, from nearly the condition of cJirysops 
to nearly the condition of terraealtae (which completely lacks 
speckling or stipples). The extent of yellow suffusion and the 
presence of yellow blotches on the anterior trunk actually varies 
from the condition of chrysops to that of terraealtae, and is 
less distinctive. The height of the caudal crest, even in old 
males, is extremely variable and cannot be used to delimit the 
taxon ; likewise, the presence of longitudinal streaking along 
the tail crest is merely an occasional character and not relevant 
to the taxon. Throat fan coloration varies tremendously; the 
condition described for MCZ 70748 is ver.y common, but the 
fan may be entirely yellow without blue-grey invasion, sharply 
divided in half between the two colors, or largely grey with 
yellow reduced to the posterior portion. One specimen, ]\ICZ 
70769, had an entirely blue-grey throat fan. In view of my 
experience with ferreus in the field, Barbour's descri])tion of 



392 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

the throat fan as grey with a wide lemon yellow margin (Under- 
wood, 1959, p. 203) is puzzling. It is suggested that Barbour 
added this note as an afterthought, based on a combined recollec- 
tion of some ferreus with Incolored fans and the fact that other 
anoles with bicolored fans often have an arrangement of center- 
color contrasted to margin-color. 

Females are likewise variable ; young specimens look very 
much like the female anole from Terre de Bas, Les lies des 
Saintes, though they would show an absolute scale size dis- 
crepancy with that form. Older specimens are notably darker 
and often greener than females of adjacent populations and often 
show a definite bluish tinge. 

Distribution: This form is confined to the island of Marie 
Galante. 

Specimens examined: MCZ 6162 (17), "Marie Galante" 
(Richardson coll.); MCZ 28526-50, "Marie Galante" (Barbour 
coll.) ; MCZ 61093-95, 62218-27, St. Louis (Proctor coll.) ; 
MCZ 62228, Les Sources (Proctor coll.) ; MCZ 70748-58, Morne 
Constant; MCZ 70759-61, Capesterre ; MCZ 70762-66, Grand 
Bourg; MCZ 70767-7], Vieux Fort; MCZ 70772-78, Ste. Ger- 
maine; MCZ 70779-84, Grelin; MCZ 70785-90, Pointe-des-Basses. 

Discussion: Anolis marmoratus ferreus is the end of a cline 
in scale size and extent of blue-grey chin pigment that begins 
on Desirade ; with respect to the extent of yellow on the lateral 
surfaces and dorsal marking it is intermediate between chrysops 
and the form next to be discussed, tcrraealtae. As with chrysops, 
terraealtae overlaps ferreus broadly in scale size, and even 
somewhat in the height of the neural spines on the caudal 
vertebrae. With respect to some characters, then, terraealtae 
is the continuation of the cline southwestward from Desirade ; 
with respect to most of its other characters it is intermediate 
between ferreus and the final population of marmoratus : caryae 
of Terre de Bas, Les lies des Saintes. 

Anolis marmoratus terraealtae Barbour 

Anolis terraealtae Barbour, 1915, Proc. Biol. Soe. Wasbiiigtoii, 128: 76. Type: 
MCZ 106127, collected by Noble, no date. 

Type locality: "Terre d'en Haut, lies des Saintes"; here 
restricted to Pompiere, Terre de Ilaut, Les lies des Saintes. 

Diagnosis: Dorsals in the standard distance 28 to 40 (average 
33); 20 to 26 (average 25) subdigital lamellae; adult male 
grey-brown to green-brown, without dark speckles or vermicula- 



LAZELL : GUADELOri'KEN ANGLES 393 

tions ; large blotches of bright yellow laterally and on nape 
fadinc to suffusions on posterior body and lielly; yellow of 
orbital area often confluent with yellow blotching of nape and 
trunk; throat-fan yellow with yellow scales. Adult female 
grey-brown with a faint flank stripe briefly indicated and a 
striped or ladder niiddorsal pattern. 

Description: An adult male from Pompiere, MCZ 70707, was 
pale brown-green, becoming browner on the head and blue- 
green on the tail. The orbital skin was ochre-yellow and suffused 
into the brown of the head. Virtually the entire costal region 
and lateral nape was blotched with three or four large areas of 
bright yellow pigment. There was no trace of dark marking. 
The throat fan was orange-yellow with yellow scales. The venter 
anteriorly was pale blue-green, almost lime-green, and faded 
to yellow in the abdominal region. Color change was merely 
to somewhat darker and browner. This specimen measured 
76 mm snout to vent; a larger specimen, MCZ 70687, from 
Pointe Basse, Grande Ilet, measured 80 mm snout to vent and 
is the largest examined. 

The adult female is pale grey-brown with a distinctly striped 
middorsal pattern. There is a short flank stripe, but it is not 
set off by darker borders above or below. 

Variation: Throat fan color varies from butter-yellow to 
orange-yellow, and the scales vary from pale to bright yellow. 
Some specimens show rather heavy yellow pigmentation of 
the entire venter. Females vary little, and no geographic 
variation was noted in either sex among the several islands 
where this form occurs. 

Distribution: A. m. terraealtae occurs throughout the low, 
dry area of Les lies des Saintes; this includes Ilet-a-Cabrit, 
eastern Terre de Haut, Grande Ilet, and, presumably, La Coche. 
This area forms a crescent around the high, wetter, western 
end of the island of Terre de Haut and lies to the east of 
the also high, wetter island of Terre de Bas. 

Specimens examined: MCZ 10628-30, "Terre d'en Haut" 
(Noble coll.); MCZ 70687-96, Pointe Basse, Grajide Ilet; MCZ 
70697-706, Ilet-a-Cabrit ; MCZ 70707-17, Pompiere, Terre de 
Haut; MCZ 70718-22, Marigot, Terre de Haut. 

Discussion: The type locality is restricted to Pompiere because 
the population on the western end of the island of Terre de 
Haut is intermediate between terraealtae and the form which 
occurs on Terre de Bas, caryac. Of fifteen specimens collected 
in the town of Terre de Haut (MCZ 70723-37), three (70730-32) 



394 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

show definite caryae characteristics of both coloration and, to a 
slight extent, squamation. Several others of this series show an 
approach to caryae on squamation. An additional series, MCZ 
70738-47, from Pointe-a-Cointe, Terre de Haut, are quite inter- 
mediate in squamation and vary considerably in color characters, 
approaching both terraealtae and caryae. The type series is 
severely discolored; on the basis of scale characters alone, how- 
ever, they fit within the range of the form which occurs in the 
low, dry "crescent" of Les Saintes. These specimens probably 
were collected in the town of Terre de Haut, but on the basis 
of what can be discerned from them the name must, ironically, 
be applied to the form which occurs on the eastern end of the 
island of Terre de Haut. There is no precise locality data with 
them that could contradict restriction of the type locality to 
Pompiere. As in the case of the Pointe-des-Chateaux population 
between inornatus and desiradei, the population on western 
Terre de Haut is not of intergrades as such, but it is one Avhich 
is both morphologically and geographically intermediate be- 
tween two very different forms and not distinctive in its own 
right. The presence of this intermediate population necessitates 
classifying the last form to be described as : 

Anolis marmoratus caryae subsp. nov. 

Holohjpe: MCZ 70666, collected 6 September 1961 by J. D. 
Lazell, Jr. 

Ty2}e locality: The town of Terre de Bas, Terre de Bas, 
Les Hes des Saintes. 

Diagnosis: Dorsals in the standard distance 38 to 53 (average 
47) ; 20 to 26 (average 23) subdigital lamellae; adult male pale 
green, becoming bright green posteriorly ; a faint wash of 
yellow on abdomen, rest of belly lime green ; fine vermiculations 
coalesce on the back of the head and the nape to produce a grey 
appearance ; posteriorly these fine vermiculations produce dis- 
tinct pale grey transverse markings; a pale, whitish flank stripe 
accentuated in the costal region by a lack of vermiculation ; 
throat fan bright .yellow with yellow scales ; orbital area cream- 
colored. Adult female pale grey-green with ladder middorsal 
pattern and striking flank stripe set off by dark speckles above 
and below. 

Description of holotypc: This adult male was pale green with 
fine vermiculations so pronounced on the head, neck and an- 
terior dorsum that the ground color appeared only as flecking 



LAZELL : aUADELOUPKEN ANGLES 395 

in this area. There was a sharp transition between this vermicu- 
lation and the grej^ transverse bands, thonjrh neither the vermieu- 
lations nor the bands were dark or bold compared to the green 
ground color. The flank stripe appeared as a continuation of 
the pale whitisli chin and throat color and extended beyond the 
first transverse band. The throat fan was bright yellow with 
yellow scales, and the orbital skin was cream-colored. The 
dorsal scales are very small though not spinose. Color change 
was negligible. The holotype, To mm snout to vent, was the 
largest specimen examined. 

Variation: The orbital skin may be pale yellow or cream- 
colored, probably depending more on the eye of the observer 
than anything else. Variation in this population is .so slight 
with respect to the known sample that it defies description. 

Distribution: This form is confined to Terre de Bas, Les Ties 
des Sainte.s. 

Paratijpes: MCZ 70667-76, same data as the type; MCZ 
70677-86, Grande Anse, Terre de Bas, Les lies des Saintes. 

Discussion: That two such different anoles occur in the 
Saintes came as a complete surprise. When I discovered this 
fact I was struck by the similarity of caryae to chrysops, for 
I had not yet seen desiradei. In general, caryae bears a re- 
remarkable resemblance to a pale, faded desiradei, though there 
is, of course, an ample set of characters to unequivocally dis- 
tinguish them. It is suggested that, aside from parts of the 
large and ecologically variable island of Marie Galante (see 
"Evolutionary Discussion"), the islands of Desirade and Terre 
de Bas are more ecologically similar than any of the other 
"satellite" islands: both are fairly high and rather homo- 
geneously wetter than any other islands in the "satellite" 
group, including Marie Galante. The similarity between the 
anoles of Desirade and Terre de Bas, Les Saintes, is in my 
opinion the product of parallelism. There is no apparent re- 
semblance between caryae and the anoles of La Guadeloupe 
except in those characters which define the species marmoratus. 
The relationships of caryae are obviously and directly to ter- 
raealtae, thence back through the stepped-cline series to desi- 
radei, which is related to inornatus in the same manner as 
caryae is to terraealtae. 

This form is named for Margaret M. Cary, who, in 1957, 
sponsored my first trip to the Caribbean; without her contiinious 
inspiration and friendship since that time my life might have 
been a very different one, and I might never have seen the 
island of Terre de Bas. 



396 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

EVOLUTIONARY DISCUSSION 

The fact that geographic variation within a single species 
has produced so many geographic units, herein described as 
subspecies, is remarkable. As I noted for A7iolis oculatvs on 
Dominica, ecological zonatioii appears to have produced this 
situation. On Dominica there are four subspecies: nominate 
oculatus, on the south coast, winstoni, on the wet, windward 
coast, cahritensis, on the dry, northern leeward coast, and 
montanus, in the central rain forest. 

Dominica is the largest and highest of the first cycle islands 
on which an Anolis of the himaculatus group occurs ; though 
somewhat smaller in area, La Guadeloupe is closely similar 
in topographical conformation, and a comparison of these two 
islands is called for with respect to their A7iolis. 

Ecological zonation is produced, among the first cycle islands 
of the Lesser Antilles, Ijy a combination of two factors: the 
predominant northeast wind and a range of high mountains. 
The predominant northeast wind may be considered as a vector 
in which the eastern component is the result of the inertia of 
the air mass surrounding the rotating earth, and the northern 
component is the result of convection currents produced by 
warmed air rising from the equatorial regions, cooling in the 
upper atmosphere, descending at the poles and pushing across 
the surface of the earth towards the equator. (In the Northern 
Hemisphere this amounts to a nortlierly wind direction.) 

The mountain factor of this etiological combination is more 
complex. Cumulus, produced directly by evaporation off the 
tropical Atlantic, can be backed up on a chain of mountains, 
providing they are high enough and sufficiently close together, 
in such a way as to produce both a rain (or "cloud") forest 
zone through the mountains themselves, and a well-watered 
lowland region to windward. The result of this to leeward of 
the mountains is a lowland zone of low rainfall and generally 
arid conditions. In Dominica a chain of mountains that are 
demonstrably high enough and sufficiently close together to 
act as a moisture barrier begins, in the south, with Moriie 
Anglais, and extends northward to the massif of Morne Dia- 
blotin. The mountains increase in height from south to north, 
in this case, and the result is a larger rain forest area, and a 
correspondingly more arid leeward coast area, at the northerii 
end of the island. There is a broad gap between the Morne Dia- 
blotin massif, however, and the smaller, lower Morne An Diable 



LAZELL : GUADEL0UP6eN ANGLES 397 

massif at the north tip of the island. Mornc An Diahh» is, how- 
ever, sufficiently high to baek up ennnilns of its own, and it 
also gets some rain from large amounts of cumulus backed up 
on Diablotin, at least during the rainy seasons of the year. 

On La Guadeloupe a similar situation prevails: a series of 
peaks comparably high and continuous begins in the south with 
the Soutt'riere-San.s Toucher massif and continues northward 
to Morne Goton. There is not, however, a smaller, disjunct 
massif corresponding to Morne Au Diable in Dominica. Also, 
the highest montane area on La Guadeloupe is at the southern 
end : the Soutfriere-Sans Toucher massif produces the largest 
rain forest area, and, correspondingly, the most arid region 
is the southern leeward coast. La Guadeloupe, then, has the 
ecological zonation of Dominica, but in mirror image. 

On Dominica, the Morne Au Diable massif is well watered 
but never attains genuine rain forest conditions even at its 
highest points. The result of this is a large area at the north 
tip of Dominica that is a sort of "ecological mongrel." Rain 
forest, as such, does not appear, but the country is decidedly 
wetter at lower elevations than elsewhere on the island. This 
area contains an anole that is morphologically intermediate 
between a coastal form (winstoni) and the montane form {mon- 
tanus), and this intermediate occurs at much lower elevations at 
the northern end of the island than do intergrades with mon- 
taniis elsewhere. 

On La Guadeloupe, where the Souffriere-Sans Toucher massif 
is at the south end, very close to the tip of the island, and 
there is no disjunct massif closer to the coast, the "ecologically 
mongrel" area is at the southern tip. It is therefore suggested 
that the presence of olliaccus influence at sea level, combined 
with coastal girafus influence, at the south tip of La Guadeloupe 
is directly the product of ecological conditions. 

It may be noted, however, that in Dominica the tip-po|)ulation 
anole is intermediate between the montane and wet, windward 
coast forms ; on La Guadeloupe the tip-population is intermediate 
between the montane and dry, leeward coasi forms. 

Anolis oculatus montanus, of Dominica, is an entirely green 
anole with a dark throat fan and white, black-bordered, lateral 
spots. Anolis marmoratus alliaceus, of La Guadeloupe, is an 
entirely green anole with a dark throat fan and black, light- 
bordered, spots. The convergence is obvious, but 1 am unable 
to account for a selection pressure which would produce such 
spot-patterns. 



398 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Similarly, Anolis oculatus cahritensis, from the arid coast of 
Dominica, has a striped pattern composed of coalescing- light 
spots on a darker ground color. Anolis marmoratus girafus, 
from the arid coast of La Guadeloupe, has pale, coalescing spot 
series. In this case the convergence seems to result from a 
selection pressure operating to produce "outline-breaking" color 
patterns in forms which occupy the sparsely vegetated scrub- 
thornbush areas of both islands. Similar "outline-breaking" 
patterns appear in most of the other dry country forms. There 
is also a correspondence between Dominica and La Guadeloupe 
dry country forms with respect to their clinality. In both cases 
a bright color begins at each end of the range and fades out 
elinally towards the middle. 

A geographical convergence may be noted between the south 
coast form of A. oculatus (nominate oculatus), on Dominica, 
and the north coast form of A. marmoratus (sctosus), on La 
Guadeloupe, but no morphological convergence is readily ap- 
parent. 

La Guadeloupe has, in reality, two wet, windward coast forms : 
nominate marmoratus and speciosus. Southwestern Grande 
Terre is ecologically confluent with the "waist" between Grande 
Terre and La Guadeloupe (which is part of La Guadeloupe), 
and there is no reproductive break between speciosus on either 
side of the narrow estuary which separates them. In fact, 
though I never stopped to collect them, anoles were seen on 
the bridge across this estuary. Riviere Saline. There is no ap- 
parent morphological convergence between either of the La 
Guadeloupe windward coast forms and winstoni of Dominica. 

The second cycle islands of the Lesser Antilles are generally 
dry. An exception is southwestern Grande Terre, which is close 
enough to the mountains of La Guadeloupe to be well-watered 
lowland. In the Guadeloupeen archipelago, two of the second 
cycle islands, La Desirade and Marie Galante, are high enough to 
get at least more rain than does northeastern Grande Terre or 
Les Ties de la Petite Terre. Desirade rises abruptly to elevations 
of nearly 300 m, and is rather high throughout. Marie Galante, 
on the other hand, is rather "lumpy" in topography, like 
southwestern Grande Terre, but neither high enough {ca. 200 m 
at the highest point) to collect much rain of its own nor adjacent 
to a mountain range that could back up rain-bearing clouds 
over it. 

The results of the above conditions are that Desirade is fairly 
homogeneous in ecological conditions and wetter than north- 
eastern Grande Terre. Marie Galante, however, is ecologically 



LAZELL : GrAOKLOlTEKX AXOLES 399 

diverse, but the diversity is not in the form of f^eoj^rapliical 
zones: dry country and rather lush, wet country alternate in 
patches all over Marie Galante. It is suggested that this complex 
situation with respect to ecology may account for the extreme 
variabiliy of A. m. ferreus on Marie Oalante. 

Further, a generalization suggests itself: wide-ranging dry 
country anoles are more variable than wet country anoles. This 
generalization would ()l)vi()usly not hold in cases like Les Ties 
de la Petite Terre and tlie low, dry "crescent" of Les Saintes 
because in these very small geographic areas the ecological 
conditions are fairly homogeneous. In the larger, generally dry 
areas, however, there are always ravines, ponds, or coastal 
marshes that provide patches of more or less lush vegetation, 
and thus ecological diversity, within the encompassing "dry 
country" region. If variability is a function of ecological diver- 
sity, then this generalization is valid. 

ACKNOWLEDGMENTS 

Without the patient assistance of Drs. H. M. Smith and E. E. 
Williams, who both read and reread this paper in many manu- 
script editions, it would probal)ly never have seen completion. 
Both Messrs. Paul Bouclier and Joseph Themine, of Point-a- 
Pitre, Grande Terre, assisted me greatly in getting to some of 
the difficult localities collected. iMiss M. A. Mertz prepared the 
translation of the summary into French. 

This work in its entirety, both in the field and in the labora- 
tory, Avas supported by National Science Foundation Grant 
G-i6066. 

SUMMARY 

A collection of 792 Anolis from 77 localities on 13 islands of the 
Guadeloupeen archipelago is reported on. The islands include 
La Guadeloupe ("Basse-Terre"), Grande Terre, La Desirade, 
Marie Galante, Ilet-a-Kahouanne, Ilet-a-Fajou, Ilet-a-Cochons 
(ou Gouvernement), both of Les lies de La Petite Terre, and 
four of Les lies des Saintes. Five previously named populations 
are reviewed and redefined : marmoratus, alliaceus, ferreus, 
speciosus, and terraealtae. Seven previously undescribed popu- 
lations are described and named : girafus, seto.ms, kahouanncnsis, 
inornains, desiradei, chrysops, and carijac. All twelve popula- 
tions are regarded as subspecies of Anolis marmorofus Dumeril 



400 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

and Bibron, 1837. The concept of Simpson's (1961) "evolu- 
tionary species" is utilized and discussed; criteria for determin- 
ing continuity of evolutionary role amono" insular populations 
are enumerated. The role of ecological zonation in subspecia- 
tion is discussed relative to Anolis marmoratus and other species 
of the himaculatus group. 

SOMMAIRE 

Une collection de 792 Anolis de 77 localites de treize iles de 
I'archipel Guadeloupeen est decrite. Les iles comprennent La 
Guadeloupe ("Basse Terre"). Grande Terre, La Desirade, Marie 
Galante, Ilet-a-Kahouanne, Ilet-a-Fajou, Ilet-a-Cochons (on 
Gouvernement), les deux lies de la Petite Terre, et quatre des 
Iles des Saintes. Cinq populations, precedemment nommees, sont 
revues et redefinies : marmoratus, alliaceus, ferreus, speciosus, 
et terraealtac. Sept populations non-decrites auparavant sont 
decrites et nommees: girafus, setosus, kaJwuannensis, inornatus, 
desiradei, chrysops, et caryae. Les douze populations sont toutes 
considerees comme sous-especes d^ Anolis marmoratus Dumeril 
et Bibron, 1837. La notion de "I'espece evolutive" de Simpson 
(1961) est adoptee et discutee ; Les criteres pour la definition 
de la continuite du role evolutif de ces populations insulaires 
sont definis. Le role de la zonation ecologique dans la formation 
des sous-especes est considere ehez Anolis marmoratus et d'autres 
especes du groupe himaculatus. 

LITERATURE CITED 

Davis, W. M. 

1926. The Lesser Antilles. Am. Geog. Soc, New York, 207 pp. 
Lazell, J. D., Jr. 

1962. Geographic differentiation in Anoli>f oculaftts on Dominica. The 
anoles of the eastern Caribbean (Sauria, Iguanidae). Part Y. 
Bull. Mus. Comp. Zool., 127(9) : 466-475. 
Simpson, G. G. 

1961. Principles of Animal Taxonomy. Columbia Univ. Press, New 
York, xii -f 247 pp. 
Underwood, G. 

1959. Revisionary notes. The anoles of the eastern Caribbean (Sauria, 
Iguanidae). Part III. Bull. INIus. Comp. Zool., 121(5): 191-226. 
Underwood, G. and E. E. Williams 

1959. The anoline lizards of .laiiiaica. Bull. Inst. Jamaica, Sci. Ser., 
9: 1-48. 



LAZELL : GUADELOUPEEN ANGLES 



401 



TABLE 1 

Home color characteristics of adult males of the twelve subspecies of Anolis 
inunuoratus in the (iuadeloupeen archipelago. 



girafus 



brown to green 
+ blue 



light 

reticulations 
setting off 
dark areas 



setosus 



green + blue 



dark, temporary, 
transverse bars 



l-ahouannrnsis 



chartreuse 
(= bright 
yellow-green) 



speciosus green -|- blue none 



iiwrnafit/^ dull greenish 



faint trans- 
verse bars; 
flank stripe 



vellow 



desiradci 



chrysops 



pale 
grey-green 



verniiculations yellow 



white 



pale 
grey-green 



vermiculations 
reduced 



ferrens 



grey-brown 
+ green 



flecking 



terraealtae 



grey-brown 
-\- green 



yellow 
blotches 



caryae pale green 



fine, pale 
vermiculations 



Sulispecies 


Ground Color 


Markings 


Tliroat Fan 


Throat Fan 


Orbital 








Skin 


Scales 


A I ea 


inarmoratus 


green -|- blue 


orange marbling 
anteriorly 


orange-yellow 


yellow 


marbled 
orange 


alUacriis 


green 


light bordered, 
dark spots 


dull orange 


green 


brown-green 
lids white 



yellow white brown 



yellow greenish dark green 



yellow yellow greenish 



yellow greenish sky blue 



white brown 



red 



yellow yellow red-gold 



yellow yellow dull yellow 

± grey ± grey 



yellow yellow dull-yellow 



vellow yellow cream -colored 



Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 

Vol. 131, No. 12 



ANOLIS EQUESTRIS IN ORIENTE PROVINCE, CUBA 



By Albert Schwartz 



With One Plate 



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Bulletin of the Museum of Comparative Zoology 

H A R V A R I) U N I V E R S I T Y 

Vol. 131, Xo. 12 



ANOLLs EQIESTUIS IX OKIEXTE PKOVIXCE, Cl'lJA 



By Albert Schwartz 



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PRINTED FOR THE MUSEUM 

September, 1964 



Bull. Mus. Comp. Zool., Harvard Univ., 131 (IJ) : 403-428, Sept., 1964 
No. 12 — Anolis cqucstns in ()>•{( ntc I'rorincc, Cuba 

By Albert Schw.xhtz ' 



IXTHODIC'TIOX 

In 1!)58, [ reviewed the suhspeeies of the C'uban <;iaiil uiiole. 
Anolis equestris. At that time, the only .specimens from Orients, 
the ea.sternmost Cuban provinee, were .sixteen individuals, all in 
rather poor condition and most of which had been in j)i'eservation 
for some time. Also, of these sixteen, nine were from the north- 
western coast of Oriente and represented the subspecies thomasi, 
thus leaving only seven lizards from the remainder of the prov- 
ince. Since tiiat time, 1 have collected a series of these anoles in 
Oriente, under National Science Foundation grant (J-()2r)2, in the 
summers of 1959 and I960; in addition, in the belief that Oriente 
equestris could best be treated as a unit and on the basis of all 
available material, Dr. Ernest E. Williams has invited me to 
study certain .specimens he was intending to describe, as well 
as certain comparative material obtained in Cuba under XSF 
Grant G-16066 or borrowed by him from the Hamburg Museum. 
The gathering together of all this material makes it possible to 
clarify the Oriente picture a bit more satisfactorily, although all 
questions are by no means answered. 

I wish to thank Ronald F. Klinikowski, David C. Leber, James 
D. Smallwood, and Barton L. Smith for th(Mi- assistance in the 
field. Mr. Klinikowski has also made the illustrations for the 
present paper. In addition to specimens borrowed from the 
Museum of Comparative Zoology (MCZ), the Hamburg Museum 
(HM), and the American Museum of Natural History (AMNH), 
for which I wish to thank Dr. Ernest AVilliams, Dr. Werner 
Ladiges, Charles M. Bogert, and Dr. Richard G. Zweifel, I have 
examined material from the Carnegie ^Museum (CM) under the 
care of Neil D. Richmond, and the Museo y Biblioteca de 
Zoologia de la Habana (]\IBZH) which was formerly under the 
curatorship of ]\Iiguel L. Jaume Garcia; specimens from the 
United States National Museum (IJSNM) are currently not avail- 
able, but I have previously taken scale counts and measurements 
on the pertinent specimens in that institution, and the loans 
were made at that time by Dr. Doris M. Cochran. All these 
curators deserve my sincere thanks for their cooperation. 

1 Present address: lO.OOO S.W, s4tli Street, Miiiiiii 4:!. Florida. 



406 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

SYSTEMATICS 

In my previous paper I referred all Oriente Anolis cquesfris 
(except those from the northwestern coastal region of Banes and 
Gibara) to the subspecies nohlei; the Banes and Gibara material 
was clearly referable to the more western race thomasi. At the 
same time, I mentioned (1958 :6) a bizarrely patterned individual 
from the Rio Yateras, which lies to the east of the Bahia de 
Guantanamo, and commented that "additional specimens from 
this area would be instructive." One other fact is worthy of 
mention: when Barbour and Shreve (1935:250-51) described 
A. e. 7Wblci, they had only three specimens, two of which were 
juveniles. The type, an adult male, is from the Sierra de Nipe, 
a poorly restricted locality ; of the two juvenile paratypes, one 
is from Santiago de Cuba and the other from near Guantanamo. 
Although immature, the Santiago de Cuba .specimen is sufficiently 
grown to demonstrate that it is not assignable to nohlei but rather 
to the race which occurs between the Bahia de Santiago and the 
Bahia de Guantanamo. The Guantanamo juvenile is so young 
that it lacks any adult pattern and has only the uniform dorsal 
ground color (presently brown, but emerald green in life) with 
a series of four paler dorsal crosstands; this coloration is gener- 
ally that of juveniles of most races of A. equestris. 

A. c. thomasi is the giant anole of the northern Oriente coast 
from the Camagiiey-Oriente line as far east as Banes. Remark- 
ably, a young specimen (snout-vent length 113 mm) from Cabo 
Cruz (AMNH 83632) is likewise clearly of this .same race (see 
Figure 1). There are no specimens of A. equestris from the 
interior of western Oriente, but on the basis of the Cabo Cruz 
and northern coastal records, the implication is clearly that 
A. e. thomasi occupies more or less the western third of Oriente. 
Considering the subspecific differentiation in A. equestris 
in the remainder of the province, this widespread distribution of 
A. e. thom^asi is rather surprising. Considering, however, the 
relative uniformity of the western third of Oriente in contrast 
to the great ecological diversity of the balance of the province, 
the widespread occurrence of A. e. thomasi is more or less to be 
expected. This more western subspecies occupies the Camagiiey- 
Tunas-Holguin subregion and the Cauto-Alto Cedro Plain (]\Iar- 
rero, 1951 :550 et seq., 636 et seq.). The former of these physio- 
graphic regions is that area occujned by thomasi in the province 
of Camagiiey, and the latter region covers most of central 
western Oriente and extends from north of the Sierra Maestra 
south almost to Cabo Cruz. 



SCHWARTZ : AXOLIS EQUESTRIS IN ORIENTE 407 

The eastern two-thirds of Oriente, as well as the entire .southern 
coast, is mountainous ; the Sierra Maestra extends from the 
vicinity of Pilon on the west (near Cabo Cruz) to the Bahia de 
Santiago on the east ; between this bay and the Bahia de Guan- 
tanamo lies the isolated but nonetheless related Sierra de Gran 
Piedra. The Sierra Maestra-Gran Piedra massif is bounded on 
the north by the valley of the Eio Cauto. The remainder of the 
province is composed of one grand mountainous mass, variously 
subdivided and of varying elevations ; in .some areas precise names 
have been associated with especiallj^ prominent ranges ; the Sierra 
de Nipe and the Sierra de Cristal are two of these, south of 
the Bahia de Nipe and to the south between the cities of Mayari 
and Sagua de Tanamo, respectively. The eastern quarter of the 
province is occupied by the extremely rugged and dissected 
mountain mass which is customarily named the Cuchillas de 
Toa. The southern coast lies in the rain shadow of the Sierra 
Maestra, Sierra de Gran Piedra, and the Sierra de Purial (a 
subdivision of the Cuchillas de Toa) ; this coastal strip is ex- 
tremely hot and xeric, with vegetation typical of such areas in 
the tropics — cacti, acacias, and many shrubby plants. The 
north coast, north of the Cuchillas de Toa, is luxuriant, and in 
many places the rain forest descends almost to the coastal beaches 
themselves. From the above brief discussion it should be obvious 
that much of Oriente is varied both climatically and physio- 
graphically; against such a setting it is not likely that A. 
equcsfris, which is tolerant of a wide variety of ecological con- 
ditions, would remain undifferentiated. 

The type locality of A. e. nohlei is the Sierra de Nipe. This 
range lies to the north of the valley of the Rio Cauto, which 
separates it from the Sierra Maestra to the south. The Sierra 
de Nipe is the westernmost portion of the large mountain mass 
of eastern Oriente. Presently, there is but a single specimen 
(the type of A. e. nohlei) of A. equestris from this area; in fact, 
the number of preserved equestris from interior localities in 
Oriente is very small. The type specimen (MCZ 26653) is a 
large adult male (snout-vent length about 152 mm) ; despite 
its length of time in preservative, the head pattern and to a lesser 
extent the body pattern are still decipherable. The body in life 
was presumably some shade of green ; presently, it is green with 
scattered brown dots on one side and brown with scattered buffy 
spots on the other. These dots are actually restricted to .single 
scales, although on occasion two or even three adjacent scales 



408 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

are unicolored and the "dot" is thus more extensive. The hind- 
limbs and the tail are obscurely banded with lighter color ; these 
bands are again actually a vertical series of scales which are set 
off from the ground color and are usually only one scale in width. 
Using the distance between the snout and the anterior border 
of the eye (hereinafter called the snout-eye distance), there are 
20 rows of scales vertically, and 24 rows of scales horizontally on 
the body included in this distance. There are 22 rows of square 
caudals in the snout-eye distance as well. 

The top of the head is mottled dark on a light background ; 
there is more light color than dark. From experience with A. 
equestris in life, I assume that the light coloration on the head 
was yellow or white, although pale green is another possibility. 
The pale head coloration extends posteriorly over the occiput and 
onto the neck, where there are two irregular pale nuchal blotches 
(see Figure 2). Laterally, the upper and lower labials are dark; 
the loreal region is dark, blending gradually into the pale canthal 
ridge. The canthal ridge continues pale above the eye and merges 
with an equally pale postorbital spot which in turn is adjacent 
to the nuchal spot mentioned above. There is a pale green post- 
labial stripe and a pale green shoulder stripe, both fairly clearly 
set off from the ground color. The eyeskin is pale brown. There 
are 11 supralabials to below the center of the eye, and about 45 
subdigital lamellae on the fourth toe. 

Before proceeding, it seems wise to mention the following prob- 
lems as far as scale counts on these giant anoles are concerned. 
Barbour and Shreve (1935: 250) diagnosed A. e. noMei partially 
by means of the number of scales around the body just caudal of 
the dewlap. In 1958 I rejected this technique as difficult and 
subject to error, and adopted the snout-eye distance as a stand- 
ard. The latter is still not completely satisfactory ; at the time 
of my 1958 paper I was studying anoles principally collected 
and preserved by myself and party. These anoles were injected 
with formalin and laid out to harden in metal pans. Thus they 
had been subjected to more or less uniform procedures, were 
slightly distended with preservative, and were uncurled and 
straight. Most scale counts which I have taken previously were 
on these uniform specimens. However, when working on 
specimens which at times are desiccated, overly injected and dis- 
tended, curled in jars, etc., I am well aware that the snout-eye 
count is subject to tremendous bias. Secondly, the fourth toe 
subdigital lamellae present a problem. I have usually counted 
only those subdigital scales which are distinctly broader than 



SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 409 

loiiii' and with free edges. These scales occupy roughly the three 
distal plialaiigos. But in some individuals these scales continue 
much farther proximally, witliout interruption ; to count to the 
"normal" stopping place at the end of the third distal phalanx 
is difficult and subject to error, and I have continued to count 
these lamellae beyond this point. Such proximad extensions ac- 
count for some unusually high count.s. 

There are at hand nine specimens of A. cquestris from tiie area 
of the Sierra Maestra which differ in several respects from the 
type of A. e. nohlei. For these lizards from the southern massif in 
Oriente I propose the name, in allusion to the large-headed males : 

Anolis EQUESTRIS GALEiFER new subspeclcs 

Type: MCZ 59326, an adult male, collected near Buey Arriba, 
southwest of Bayamo, Oriente Province, Cuba, by Kamon 
Molina and Rodolfo Ruibal, 17 July 1959. 

Paratijpcs: MCZ 59325, same data as type; AMNH 83627, Las 
Mercedes, 27 km S Yara, Oriente Province, Cuba, collected by 
Ronald F. Klinikowski, 7 July 1959; HM 5261 (4 specimens), 
mountains near Guisa, Oriente Province, Cuba, collected by 
Thumb, October, 1936; MBZH 142, near Loma del Gato, El 
Cobre. Santiago de Cuba, Oriente Province, Cuba, collected by 
C. T. Ramsden and Hno. Cristostamo, no date ; HM 5936, 
"Oriente," Cuba, collected by Thumb, 1936. 

Distribution: Apparently the region of the Sierra Maestra 
from Las Mercedes on the west to Loma del Gato on the east. 

Diagnosis: A subspecies of Anolis equestris characterized by a 
combination of large size, moderately-sized dorsal and caudal 
scales without white skin streaking ; unspotted dorsum ; a prom- 
inent pale postorbital blotch but no nuchal extension thereof; a 
short and indistinct postlabial stripe and a prominent and long 
shoulder stripe ; dewlap pink. 

Description of type: An adult male with both luMnipenes 
extruded, snout-vent length 183; tail 340 (all measurements in 
millimeters) ; dorsals (counted vertically) in snout-eye distance, 
19; dorsals (counted horizontally) in snout-eye distance, 21; 
caudals (counted horizontally) in snout-eye distance, 23; supra- 
labials to below center of eye, 10; enlarged scales on under- 
surface of fourth toe, 47. 

Head longer (54.0) than broad (34.2), snout rather acumi- 
nate but rounded; canthus rostralis of six enlarged and peaked 
scales; 38 loreals on one side, the uppermost row more or less 



410 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

rugose, the remainder smooth; dorsals quadrate, subquadrate or 
even rectangular, separated by numerous tiny scales ; 29 en- 
larged dorsals between slightly smaller and more regular belly 
scales and medial dorsal row of flaccid crest scales, largest mid- 
way between fore- and hindlimb insertions on sides ; about 31 
smaller scales on belly between lowermost rows of enlarged 
laterals, gradually increasing in size from midventer laterally ; 
dorsal surface of limbs covered with pavement-like scales about 
two-thirds the size of enlarged laterals; ventral surface of limbs 
covered with scales about one-half the size of midventrals ; ventral 
edge of dewlap with scales considerably smaller than mid- 
ventrals, largest anteriorly. 

Coloration: The preserved specimen is bluish dorsally and 
dark brown laterally; there is no indication on the dorsum, 
limbs, or tail, of any dotting, spotting, or crossbanding. The 
ground color of the limbs is blue, as is that of the tail. The 
dewlap still has a faint pink tinge and the venter varies from a 
bluish cream to brown. I gather from the present coloration that 
this lizard was green in life, with no spotting or crossbanding. 
The casque is presently dark brown with a minimum of paler 
spotting ; there are a few isolated spots on the snout and a few 
on the occipital region. The canthus is pale and expands poster- 
iorly into a prominent postorbital blotch (see Figure 3). The 
labials, lores, and eyeskin are dark brown. The postlabial stripe 
is short and indistinct, and the shoulder stripe is long, dark 
gray, and likewise indistinct. 

Variation: The paratypes include four males, two females, 
and two juveniles ; the entire assemblage varies in snout-vent 
length from 89 to 173, two of the paratypic males reaching the 
larger dimension. The type is, as previously noted, larger than 
either of these two males. Of the males, the three adults re- 
semble the type closely in pattern; none is spotted, the postlabial 
stripe is indistinct, and the shoulder stripe is long and fairly 
prominent. All have a pale canthus and boldly delineated post- 
orbital blotch. The top of the casque is about as described for 
the type in one specimen (HM 5261), whereas the remaining 
two adult males have the casque marked with somewhat more 
pale areas, with always more dark than light pigmentation. 
There i.s never an extension of tlie pale area onto the nuchal 
region, although all four male paratypes show at least an indica- 
tion of a single pale nuchal spot ; one specimen has a few 
scattered pale nuchal blotches which are not especially well de- 
fined. The young male (MBZH 142) has the casque somewhat 



SCHWARTZ: ANOLIS KQTTKSTRIS IX OKIKXTK 411 

iiulistiiu'tly marbled. Tliis li/ard also lacks a postorhital blotch. 
The two females show much the same variation as the males, 
althoujih both liave postorhital blotches and some indistinct neck 
blotchinj?. The shoulder stripe is poorly defined and the labial 
stripe is likewise not especially prominent, althoup:h it is dis- 
cernible. The two juveniles also show the postorhital blotch; in 
these lizards the postlabial and shoulder stripes are more prom- 
inent than in adults. The dorsal seale.s vary vertically between 
17 and 24, vary horizontally between 19 and 28, and there are 
between 44 and (51 fourth toe lamellae. 

Altliouji'h I have <>r'ouped the comparisons of the Oriente sub- 
species of A. equestris at the end of the present paper, it is ap- 
propriate here to compare .1. (. (jalcifcr with A. e. nohlri. From 
the outset it should be obviou.s that such comparison is greatly 
hampered l)v there bein": available but a single specimen of 
vohlri, as presently defined — i.e., the type. A. c. galeifer differs 
from Uijbld in having distinctly larger dorsal scales; there are 
20 in the snout-eye distance vertically and 24 horizontally in the 
type of nohlei. These figures are w'ithin the known range of 
galcifcr; however, inspection of the scales of the type of nohlei 
shows that they are distinctly smaller than those of comparably 
sized specimens of galeifer. In this case, observation is more use- 
ful than actual employment of the vernier : my comments on 
differences in preservation methods of these specimens in a fore- 
going paragraph are most pertinent. 

In addition, the paftei-n of the two races is distinctive: no 
galeifer has extensive mu'hal blotching as does nohlei. A. c. 
nohlei is dotted dorsally and has crossbanded limbs and tail ; 
galeifer does not. The extensive postlabial .stripe in nohlei con- 
trasts with the absence or reduction of this stripe in galeifer. The 
shoulder stripe is narrow and long in galeifer, but is bi-oad and 
long in nohlei. 

The dewlap coloration in nohlei is unknown ; presently, the 
dewlap of the type is a faded yellow but this is not trustworthy 
since Barbour and Shreve (1935:2')1) noted that the dewlap of 
the type was at the time of their description decidedly pinkish, 
a much more likely coloration. I have seen one A. e. galeifer, the 
female from Las Mercedes, in life; the dewlap coloration of this 
lizard wa.s noted as pink. 1 assume that both nohlei and galeifer 
have pink dewlaps : there may of course be a difference in pre- 
cise shade. 

The situation involving these two subspecies is complicated due 



412 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

to the absence of an adequate sample of nohlei. However, the oc- 
currence of one race of A. equestris in both the Sierra de Nipe 
and the Sierra Maestra is not likely zoogeographically. The 
former is separated from the latter by the valley of the Rio 
Cauto; the form of A. equestris in this valley is presently un- 
known. It is not improbable that A. e. thomasi occurs there (as 
noted above), or the valley may be a region of intergradation 
between nohlei and galeifer. 

I have previously examined one specimen (USNM 29784) 
which may possibly be associated with galeifer. This lizard, an 
adult female, snout-vent 150, is from Guama and is presently not 
available. My notes indicate that it is unspotted (and thus not 
assignable to the race described below, nor wuth the dotted 
nohlei), and that it likewise had no shoulder spots. The village 
of Guama was located about 40 miles due west of Santiago de 
Cuba, near the coast (Stejneger, 1917: 260). The dorsal scales 
of the lizard number 19 vertically and 23 horizontally, and thus 
are within the known range of galeifer. If the mining camp of 
Guama was actually in the Sierra Maestra or the foothills of this 
range, it is most probable that this specimen is representative 
of A. e. galeifer. It should l)e re-inspected to determine its sub- 
specific status; for the moment I regard it tentatively as 
A. e. galeifer. 

The southern Oriente coast between Cabo Cruz and Cabo 
Maisi has been shown to harbor a number of races of iguanid 
lizards of the genus Leiocephalus (Hardy, 1958; Schwartz, 
1960) ; two coastal features which seem to have an isolating effect 
on lizard populations in this region are the Bahia de Santiago 
and the Bahia de Guantanamo. The same features have played 
a role in differentiation of A. equestris along the xeric coast. In 
the area between these two bays, a very distinct subspecies of the 
Cuban giant anole has developed. I take pleasure in naming this 
form for James D. Small wood who collected the greater portion 
of presently available specimens, as : 

Anolis equestris small woodi new subspecies 

Type: AMNH 89526, adult male, from Laguna de Baconao, 
Oriente Province, Cuba, James D. Smallwood collector, 9 August 
1960. (Original number 9761.) 

Paratypes: AMNH 89525, 9.4 mi. W Laguna de Baconao, 
Oriente Province, Cuba, J. D. Smallwood collector, 9 August 
I960; AMNH 89527-30, Laguna de Baconao, Oriente Province, 
Cuba, J. D. Smallwood collector, 17 August 1960. 



SCHWARTZ: ANOLIS EQUESTRIS IN ORIENTE 413 

Distribution: Xeric coast between the Bahia de Santiago and 
the Bahia de Guantanamo, Oriente Province, Cuba; see, how- 
ever, discussion below. 

Diagnosis: A subspecies of Anolis equestris characterized by 
a combination of moderate size, moderately-sized dorsal and 
caudal scales without white skin streaking, leopard spotted 
dorsum (the spots encompassing as many as six adjacent scales 
and becoming elongate and linear anteriorly), a pale green post- 
labial stripe and pale greenish-yellow occiput, dewlap pink. 

Description of type: An adult male, snout-vent length 155; 
tail 298; dorsals (counted vertically) in snout-eye distance, 19; 
dorsals (counted horizontally) in snout-eye distance, 22; caudals 
(counted horizontally) in snout-eye distance, 26; supralabials 
to below center of eye, 9 ; enlarged scales on undersurface of 
fourth toe, 48. 

Head longer (45.3) than broad (30.0), snout rounded; canthus 
rostrali.s of six enlarged rugose and peaked scales ; 26 smooth 
loreals on one side ; dorsals quadrate or subquadrate, separated 
by numerous tiny scales ; 23 enlarged dorsals between slightly 
smaller and more regular belly scales and medial dorsal row 
of flaccid crest scales, largest midway between fore and hindlimb 
insertions on sides; about 29 smaller scales on belly between 
lowermost rows of enlarged laterals, gradually increasing in size 
from midventer laterally ; dorsal surface of limbs covered with 
pavement-like scales about one-third to one-half the size of en- 
larged laterals; ventral surface of limbs covered with scales 
comparable in size to midventrals; ventral edge of dewlap with 
scales slightly smaller than midventrals, largest anteriorly. 

Coloration : Tn life, dorsum green with pale green leopard-like 
spotting, the spots involving as many as four adjacent scales and 
well separated from one another, and becoming linear on the 
anterior third of the body ; eyeskin greenish gray ; a pale green 
postlabial stripe onto the neck, bordered above and below by 
darker green and sharply and prominently delimited both above 
and below ; shoulder stripe bright yellow ; top of head greenish 
yellow, the occipital area pale pea-green with scattered dark 
green blotches; lores pale green mottled with dark green (see 
Figure 4) ; scales on throat and anterior portion of dewlap dark 
green; dewlap pink (PI. 2A9 ; color designations from Maerz 
and Paul, 1950). Hindlimbs with pale green transverse lines, 
which are also partially indicated proximally on the tail. Venter 
dark green. 



414 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Variation : The paratypes include two males and three f emaless, 
varying in snout-vent length from 144 to 159. Coloration of the 
series is remarkably uniform. A female from 9.4 mi. W Laguna 
de Baconao had a dewlap which was PI. 1P9 in life (Maerz and 
Paul) ; the dewlaps in the remainder of the series were noted 
as grading from faintly orange to pink. All are spotted, although 
the spotting varies in extent; I cannot detect any difference in 
spotting between the sexes. The elaborate head pattern is 
manifested in all, although one female shows it a little less 
prominently than the remainder of the lot. The dorsal scales 
vary vertically between 18 and 21, vary horizontally between 
18 and 22 ; caudal scales vary between 23 and 26, and there are 
between 48 and 51 fourth toe lamellae. Inspection of the above 
data shows that, at least in this restricted sense, A. e. smallwoodi 
is a small, compact group of lizards with very limited variation 
in coloration and scalation. 

A.s one progresses away from the immediate coastal area be- 
tween the two bays — the type locality of smallwoodi — the 
situation becomes more complex. There are seven additional 
specimens from this general area which require some comments. 

There is a single juvenile (AMNH 89532, snout-vent 61) from 
Playa Juragua which, when collected, still had the vivid green 
dor.sal coloration with four creamish-white dorsal bands partly 
broken into spots. Playa Juragua lies 3.7 mi. east of Siboney, 
and is thus to the east of the Bahia de Santiago ; I regard this 
specimen as smallwoodi purely on the basis of provenance. It is 
possible that the broken condition of the dorsal bands is a 
characteristic of juvenile smallwoodi ; on the other hand, the 
broken bands may be merelj^ a transition stage between juvenile 
and adult patterns. 

Two specimens from Santiago de Cuba (MCZ 6924; IISNM 
58855) and one from 4 km north of Santiago de Cuba (AMNH 
89531) are instructive. One of these is a young lizard (snout- 
vent 97) which shows the dark dorsal coloration and light cross- 
bands, but in addition clearly shows the pale occiput and in- 
cipient dorsal spotting characteristic of smallwoodi. 

The second Santiago de Cuba specimen (USNM 58855) is a 
young female ; the specimen is presently not at hand, but I have 
previously examined it. My notes indicate that it has a light 
nuchal spot behind the occiput and a shoulder spot which is 
represented by only its own small dark border. There is no 
mention of any dorsal spotting, pale occipital patches, pale post- 
labial line, etc. — in fact, nothing to ally it to A. e. smallwoodi. 



SCHWARTZ : AXOLIS EQUKSTRIS IX OUIKX IK 415 

In addition, the dorsal and caudal scale counts (vertical, 10; 
horizontal, 17; caudal, \H) are extremely small and completely 
outside the known variation of small ivoodi. Likewise it cannot 
be regarded as iiohli i or (jaU i(( r Un- reasons of scalation. I can 
only surmi>e that tliis individual is not from Santiajro, nor for 
that matter from Oriente; additional inspection is imperative. 

The third Santiago specimen is from 4 km north of the city, 
and thus is in the foothills of the Sierra de Boniato at an eleva- 
tion of approximately 1000 feet {ca. 300 m) ; this specimen was 
seen alive by myself. It is a young' female (snout-vent 138) which 
was green in life with the old juvenile bands still i)resent and 
orange in color. Between the juveinle bands there are vertical 
rows of spots; the hindlimbs are banded as is the base of the 
tail. All the above might well be smallwoodi characteristics. The 
head, however, is dark dorsally, the occipital region is only 
slightly paler than the dorsum and the postlabial line, although 
prominent, is not so light nor so prominent as in smallwoodi. The 
shoulder stripe likewise is somewhat more prominent than in 
smalhvoodi. Vertical dorsals are 19, and thus within the limits 
of smallwoodi. I suspect that, despite the absence of the occipital 
pale areas (a feature which we know from the juvenile specimen 
discussed above appears very early in life), this lizard should 
be regarded as the coastal form. Some of its peculiarities may be 
due to the influence of the adjacent galcifer or another, more 
northern rather than western, form, as yet unknown. 

A fine well preserved adult male (MBZH 260) from Hongo- 
losongo is another puzzle. Hongolo.songo lies to the west north- 
west of El Cobre and is on the northeryi slope of the Sierra del 
Cobre to the west of the Bahia de Santiago. I have no doubt 
that this individual is referable to smallwoodi ; it possesses the 
pale head and occiput, dor.sal spots, etc., and the scales are 
completely within the range of topotypic smallwoodi. If we 
a'>sume that the two available specimens from the area of 
Santiago de Cuba (eliminating the single peculiar USNM 
specimen as noted above) represent smallwoodi, then clearly 
there is no gap between coastal specimens from ea.st of the Bahia 
de Santiago and the single individual from Ilongolosongo. It 
is remarkable, however, that a lizard which occurs in the xeric 
coastal plain in this region should also occur on the noi'th side 
of a somewhat removed range of mountains, but such indeed seems 
to be the case. Apparently the races smallwoodi and galcifer 
intergrade somewhere between Loma del Gato and Hongolosongo, 
a distance of about thirty miles. 



416 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

There are two available specimens from the coast (or nearly 
so) west of the Bahia de Santiago. One of these (USNM 29784) 
from Guama has already been commented upon under the dis- 
cussion of A. e. galeifer, with which race I temporarily associate 
it. The absence of dorsal spotting disqualifies it at once as being 
smallwoodi. The other lizard (MCZ 42480) is a juvenile (snout- 
vent 50) from the coast south of Pico Turquino. It shows the 
typical juvenile pattern and coloration, and there is nothing 
distinctive about it. Since it is coastal (P. J. Darlington coll.), 
it may be assignable to smallwoodi. Only additional specimens 
from this region will allow a definite subspecific allocation. 

When in 1958 I examined the available material from Oriente, 
there was a single specimen from the Rio Yateras (CM 33320) 
which was so unusually patterned that it was only with extreme 
uncertainty that I assigned it to nohlei. Since that date, another 
such specimen has come to light (MCZ 68921). In addition, I 
have examined still another specimen which I regard as belong- 
ing to this same heavily spotted form, for which I propose the 
name palardis as an anagram of the Latin word pardalis, mean- 
ing "leopard." 

Anolis equestris palardis new subspecies 

Type: CM 33320, adult male, Rio Yateras, 5 mi. north of the 
river mouth, Oriente Province, Cuba, Wm. McLane and R. H. 
Wilkinson, collectors, 16 September 1952. 

Paratype: MCZ 68921, Guantanamo (U. S. Naval Base), 
Oriente Province, Cuba, R. Lando, collector, 1962. 

Distribution: Apparently the Guantanamo Basin and east- 
ward along the southern Oriente coast presumably at least as 
far as Baitiquiri. 

Diagnosis : A subspecies of Anolis equestris characterized by a 
combination of moderate size, moderately-sized dorsal and caudal 
scales without white skin streaking, heavily spotted or almost 
reticulate dorsum, the spots encompassing as many as fourteen 
adjacent scales and parts thereof and becoming elongate and 
linear anteriorly, prominent pale postlabial and shoulder stripes, 
a prominent pale postocular patch, upper surface of casque dark 
with discrete pale flecking or with more extensive pale marbling. 

Description of type: An adult male, snout-vent length 150; 
tail (incomplete and regenerating) 120; dorsals (counted vertic- 
ally) in snout-eye distance, 14; dorsals (counted horizontally) 
in snout-eye distance, 16; caudals (counted horizontally) in 



SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 417 

snout-eye distance, 14 ; supralabials to below center of eye, 10 ; 
enlarged scales on undersurface of fourth toe, 59. 

Head longer (45.0) than broad (28.0), snout rounded; canthas 
rost rails of six enlarged rugose and peaked scales; 32 smooth 
loreals on one side; dorsals quadi'ate to subcircular, separated 
by numerous tiny scales ; 28 rows of enlarged dor.sals between 
slightly smaller and more regular belly scales and medial dorsal 
row of flaccid crest scales, largest midway between fore- and 
hindlimb insertion on sides ; about 8G smaller scales on belly 
between lowermost rows of enhirged laterals, the midventral 
scales only slightly smaller than the lower row of laterals; dorsal 
surface of limbs covered with pavement-like scales about one- 
third to one-half the size of enlarged laterals ; ventral surface 
of limbs covered with scales two-thirds the size of midventrals ; 
ventral edge of dewlap with scales slightly smaller than mid- 
ventrals, largest anteriorly. 

Coloration: The preserved specimen is almost chocolate brown, 
the entire dorsum covered with rather large and very prominent 
pale spots, the largest encompassing six adjacent scales; both 
fore- and hindlimbs are erossbanded with pale buffy, and the 
proximal portion of the tail is especially prominently erossbanded 
with narrow bands one to three scales in width. The dorsal 
surface of the head is dark brown with clear and discrete white 
flecks scattered more or less uniformly ; the occiput is dark with 
a few white flecks like those on the casque, and these extend onto 
the neck where there is a single larger white spot. The canthus 
and eyeskin are pale and there is a conspicuous and clearcut 
white postorbital blotch ; the postlabial stripe is somewhat less 
prominent and the shoulder stripe is very long, not quite so 
pale, and extends almost half-way along the body beyond the 
forelimi) insertion (see P'igure 5). There is a peculiar pale U- 
shaped figure over the sacrum which is washed with brown and 
which even now stands out conspicuously among the large dorsal 
spots. The ventral surface is dark; both supra- and infralabials 
are dark centered and pale edged ; the throat is more or less 
clouded longitudinally with dark brown. The dewlap is pres- 
ently entirely w'hite. 

Variation: The single paratype is a rather poorly preserved 
adult male with a snout-vent length of 168. The coloration and 
pattern resemble those of the type very closely except that the 
body spots are even larger and more extensive, involving as 
many as fourteen adjacent scales. The limbs and tail are boldly 



418 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

banded, the bands on the tail as wide as three caudal scales. The 
casque is likewise more prominently .spotted than that of the 
type. Other head and stripe details are comparable between the 
two, except that the postlabial and shoulder stripes are paler and 
thus show more contrast with the almost black ground color. 
The dewlap is still faintly pink. Scale counts on the paratype 
are : vertical dorsals, 18 ; horizontal dorsals, 24 ; caudals, 24 : 
fourth toe lamellae, 45. The difference in size of dorsals between 
the type and paratype is doubtless an artifact of preservation 
since by inspection the size of the dorsals does not seem to differ 
strikingly. 

As with A. e. smallwoodi, once the immediate region of the 
type locality is left, the specimens become problematical. There 
are available five other lizards which in theory should be assign- 
able to palardis. Each will be discus.sed separately. 

There is a young adult male (MCZ 42552) from Imias, which 
lies about 35 miles to the southeast of Guantanamo, on the coast ; 
this locality is the farthest east from which A. equestris is known. 
I find it very difficult to assign this individual to palardis, to 
which race it might reasonably be expected to belong on the basis 
of geography. The body shows no signs of spotting of any sort ; 
on the other hand, there is a large, conspicuous, dark bordered 
nuchal spot, and some dissociated spots on the occipital region. 
The casque is apparently marbled as in palardis, however. There 
is a pale postorbital spot, a pale and prominent i)ostlabial stripe, 
and a fairly well exj^ressed shoulder stripe, although the latter 
is not so bold nor so clear a.s that in palardis. Also, the dorsal 
scales are much smaller than are those of any specimens of 
palardis. There are two possibilities: 1) the lizard came from 
the mountains to the north of Imias, and thus represents still 
another Oriente race; 2) the lizard came from the coast at Imias 
and there is another subspecies of A. equestris along the southern 
Oriente coast beyond Baitiquiri, and thus including Imias. I 
prefer to believe that the former is the correct interpretation. 
It is even conceivable that A. e. galeifer extends this far east 
throughout the southern Oriente mountains. The Imias lizard in 
some pattern details resembles the more western race. IIoAvever, 
the small size of the scales prevents tliis si)eeiim'n from being 
associated with galeifer. 

An adult female from Baiti(|uiri (MCZ 42551) agrees very 
well with the type and paratype insofar as head pattei-n is con- 
cerned, and in fact seems to combine the cas(|ue flecks of ihe type 
with the more blotchy casque markings of the ]iaratyi)e. The 



SCHWARTZ : ANOLIS KQUESTRIS IN ORIENTE 419 

body is not particularly sjxjttcd ; witli a little imagination one 
can visualize the remnants of spots on the back and sides, but 
if they were present, tiiey were probably not so vivid and prom- 
inent a.s described above. At least the neck is marked with 
eloni^ate pale blotches and streaks very comparable to those of 
the paratype. I rejifard this specimen as palardls. 

Three specimens from the environs of Guantananio (MCZ 
8977, a juvenile, snout-vent 47, from "near Guantananio"; 
USNM 58057, an adult female, and MCZ 57928, an adult male, 
both from Guantananio) are especially puzzling. Of these the 
juvenile lacks any characteristics which would alif?n it with 
palardis; it is interesting, however, in that, of the few juveniles 
available from Oriente, it alone has a prominent pale green 
I)ostlabial stripe. l^SNM 58057 is not available at the moment, but 
my notes on it state that it has a large and elaboi'ate shoulder 
spot ; obviously the specimen i.s not entirely spotted as are the 
type and paratype of palardis. The presence of the shoulder 
spot may again indicate the same situation as noted above for 
the Baitiquiri specimen, i.e., a remnant of the more extensive 
pattern. 

The final Guantananio specimen, MCZ 57928, is distinctly dif- 
ferent from the typical material. The casque is entirely marbled 
with pale color. The postorbital spot is absent but there is a 
bi'own patch in the area bounded above by a raised i)atch of pale 
scales ; the postlabial and shoulder stripes are not pale or especi- 
ally prominent, and the dorsum shows only faint indications of 
having been spotted in life. Again, if this specimen came from 
''Guantananio" in a broad sense only, and not from the lowlands 
in the Basin itself, it is likely that it is not palardis but some 
other race from the mountains to the north. T regard it only 
provisionally as palardis. 

In the summer of 1959, I secured three A. equestris from 
Baracoa on the northeastern coast of Oriente. The dewdap colora- 
tion of these lizards was so very distinct that it was obvious they 
represented a new subspecies; Dr. Williams had also come to 
the same conclusion based upon three specimens in the collection 
at Harvard, but he has graciously allowed me to describe this 
new race as : 

Anolis equestris baracoae new subspecies 

Type: MCZ 57404, adult female, Baracoa, Oriente Province, 
Cuba, P. A. Adams, collector. 4 April 1958. 



420 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

Paratypes: MCZ 47050, Joar, Baracoa, Oriente Province, 
Cuba, G. Canet, collector, 1943 ; AMNH 83628, Baracoa, Oriente 
Province, Cuba, native collector, 11 August 1959 ; AMNH 
83629-30, Baracoa, Oriente Province, Cuba, native collector, 
13 August 1959. 

Distribution: Known only from the type locality. 

Diagnosis: A subspecies of Anolis equestris characterized by 
small size, extremely small dorsal scales and long dorsal crest 
scales, dorsum either plain green or green with pale blue small 
dots or flecks, a small and relatively inconspicuous postorbital 
patch, shoulder stripe and postlabial stripe inconspicuous and 
short, dewlap bluish-green. 

Description of type: An adult female, snout-vent 158, tail 186, 
regenerated tip; dorsals (counted vertically) in snout-eye 
distance, 26; dorsals (counted horizontally) in snout-eye dis- 
tance, 33; caudals (counted horizontally) in snout-eye dis- 
tance, 29 ; supralabials to below center of eye, 9 ; enlarged scales 
on undersurface of fourth toe, 42. 

Head longer (43.7) than broad (25.0), snout rounded; canthus 
rostralis of six enlarged rugose scales ; about 36 smooth loreals 
on one side; dorsals subcircular, separated by numerous tiny 
scales ; dorsal crest scales elongate ; 38 enlarged dorsals between 
slightly smaller and more regular belly scales and medial dorsal 
row of flaccid crest scales, largest midway between fore- and 
hindlimb insertions on sides; about 30 smaller scales on belly 
between lowermost rows of enlarged laterals, gradually increas- 
ing in size from midventer laterally ; dorsal surface of limbs 
covered with pavement-like scales about two-thirds the size of 
enlarged laterals; ventral surface of limbs covered with scales 
about one-half the size of midventrals ; ventral edge of dewlap 
with scales one-half the size of midventrals, not appreciably en- 
larged anteriorly. 

Coloration: In preservation, dorsum pale bluish -gray dotted 
with pale spots which are more or less linear and involve as 
many as four longitudinally adjacent scales. Dorsal surface on 
hindlimbs rather obscurely crossbarred with darker ; forelimbs 
with a few pale scales which apparently indicate crossbands 
in the living animal. Casque pale blue dorsally with no pale 
mai'kings; a pale blue postorbital blotch, a very indistinct post- 
labial stripe and a fairly extensive dark shoulder stripe (see 
Figure 6). Loreals and supralabials marbled with dark blue; 
throat clouded with dark ; venter immaculate pale blue. 



SCHWARTZ : ANOLIS EQUESTRIS IN OBIENTE 421 

Variation: The four female paratypes vary in snout-vent 
length from 120 to 145, and are thus all smaller than the type. 
One (AMNII 8;]628), the smallest, is colored quite comparably to 
the type; another (AMNH 83630) is very dark and is flecked 
with isolated and discrete tiny dots dorsally ; the remainino; two 
specimens are bluisii-gray dorsally without any dots or flecks, 
but show some irregular pale nuchal areas, and one of these has 
a fairly bold and prominent postorbital patch. In none are the 
postlabial and shoulder stripes really well defined. In the three 
live specimens which I have seen, the dewlap color was noted 
as blue or blue-green. It is unfortunate that all the specimens 
of haracoae are females, but judging from my experience with 
other races, the dewlap coloration is very close in the two sexes. 

The small size of the dorsal scales is manifested in the follow- 
ing figures : vertical dorsals, 25 to 27 ; horizontal dorsals, 23-26 ; 
horizontal eaudals, 20-29. 

In addition to the type and paratypes, I have seen one juvenile 
(MCZ 42520, .snout-vent 48) ; interestingly, the dorsals on this 
small lizard are indeed tiny and thus conform with the small 
scales of haracoae. Also, the lizard shows none of the dorsal 
crossbars which are usually typical of very young A. equestris. 
This patternless condition may be a character of juvenile 
baracoae. 

It is appropriate here to discuss one other lizard from the 
environs of Baracoa. It is an adult female (AMNII 83631), 
snout-vent 160, from 8 miles northeast of Felicidad. This locality 
lies more or less equidistant between Guantanamo on the south 
and Baracoa on the north. The lizard might be reasonal)ly sup- 
posed to be assignable either to haracoae or to some intergradient 
population between haracoae and palardis. The former is cer- 
tainly not the case, since the dewlap was recorded in life as being 
pink. Likewise my color notes in life (dorsum green with light 
green dots which turned brown after death ; head brown with 
cream colored casque, flecks extending onto the nape and a few 
on dorsal crest scales; lips, labial stripe and shoulder stripe 
bright green ; no occipital or shoulder blotches ; dewlap scales 
pale yellow on a pink — PI. 1E7 — skin) indicate that this lizard 
was not colored as is haracoae. The dorsal scales (vertical 23; 
horizontal, 21) are also perceptibly bigger than in haracoae and 
the dorsal crest scales are not high and elongate. In some ways 
this specimen resembles ]\ICZ 57928 from Guantanamo, but it 
is just as distinctly different. I regard it pro tern as a representa- 
tive of a race from the mountains of interior of eastern Oriente. 



422 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

Four specimens of A. equestris from the region of Moa on the 
north Oriente coast represent still another indigenous subspecies, 
which may be called, in allusion to the pebbly appearance of the 
dorsal surface of the casque : 

Anolis equestris saxuliceps new subspecies 

Type: HM 5376, adult female, Moa, Oriente Province, Cuba, 
Thumb, collector, between April and November, 1938. 

Paraiypcs: HM 5376 (smaller of two specimens bearing this 
number), same data as type; HM 5374, same data as type; MCZ 
59324, cfl. 7 km B Moa, Oriente Province, Cuba, R. Molina and 
R. Ruibal, collectors, 21 July 1959. 

Distribution: Known onl}- from the immediate environs 
of Moa. 

Diagnosis: A subspecies of Anolis equestris characterized by 
a combination of moderate size, moderately sized dorsal and 
caudal scales without white skin streaking, dorsal coloration ap- 
parently somewhat dotted or spotted, prominent and dark 
bordered postlabial and shoulder stripes, absence of postorbital 
blotch, dorsal surface of casque with a reticulate or marbled 
appearance, spotted labials, dewlap pink. 

Description of type: An adult female, snout-vent length 146; 
tail 187; dorsals (counted vertically) in snout-eye distance, 20; 
dorsals (counted horizontallj-) in snout-eye distance, 21 ; caudals 
(counted horizontally) in snout-eye distance, 24; supralabials to 
below center of eye, 10 ; enlarged scales on undersurface of fourth 
toe, 44. 

Head longer (42.2) than broad (25.9), snout rounded; canthus 
rostralis of 6 enlarged rugose scales ; 43 loreals on one side, 
smooth except that the two upper rows are somewhat rugose ; 
dorsals subquadrate, separated by numerous tiny scales ; 29 en- 
larged dor.sals betM^een slightly smaller and more regular belly 
scales and medial dorsal row of flaccid crest scales, largest mid- 
way between fore- and hindlimb insertions on sides; about 33 
smaller scales on belly between lowermost rows of enlarged 
laterals, gradually increasing in size from midventer laterally ; 
dorsal surface of limbs covered with pavement-like scales about 
one-half the size of enlarged laterals ; ventral surface of limbs 
covered Avitli scales about one-half the size of midventrals ; 
ventral edge of dewlap with scales slightly smaller than mid- 
ventrals, not appreicably larger anteriorly. 



SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 423 

Coloration: Tho typo is now dark l)rown dorsall}-, and dirty 
bluish pray ventral ly. The middorsal area has a few scattered 
lipht blue scales, and tlicre is a taint indication of at least two 
vertical lateral bands of buft'y scales between the limbs. I do 
not know exaetl}' what the significance of these details is, havinf? 
never seen saxidiceps in life. Tt is pos-sible that dorsally the 
lizard was green in life with some middorsal pain- flecks and a 
pair of pale green lateral bars, all of which likelj' M'ere rather 
inconspicuous. The hiudlimbs are unmarked, whereas the fore- 
limbs and dorsal surface of the hand show some paler scales, 
which at least on the forearm are organized into erossbands. 
The most striking feature is the gravelly appearance of the 
casque. Each scale on the dorsal surface of the cascjue is pale 
centered and dark edged, giving the casque a more or le.ss uni- 
formly marbled or even reticulate appearance; this pattern con- 
tinues posterioi'ly over the top of the head as far as the occiput 
and into the postorbital region (which is indistinctly and finely 
marbled), then blends imperceptibly into the dorsal body dotting 
mentioned above. The lores, supra- and infralabials are likewise 
pale with much dark marbling, the dark pigment on the labials 
being placed at the sutures between the scales, rather than in the 
center of the scales (see Figure 7). The eyeskin is dai-k brown. 
The mental area is dull blue, grading quickly to very dai'k brown 
at al)out the level of the anterior edge of the dewlap, and this 
brown coloration continues posteriorly to the forelimb insertion. 
The dewlap skin is presently dirty cream. The postlabial line 
is pale blue, clearest anteriorly but still very obvious and 
bordered above and below with darker on the neck. The shoulder 
stripe resembles the postlabial stripe in clearness, definition, and 
in being bordered with darker above and below. 

Variation: The three paratypes are females, one of which is 
rather immature, ranging in snout-vent length from 112 to 132. 
As far as head pattern is concerned, all resemble the type very 
closely. The same is true of body pattern and coloration, except 
for the smallest (HM 5374). This young female has a streaked 
dorsum, the individual streaks involving three scales on the body 
itself, and more in the scapular region. The neck is almost 
reticulate, there being more pale than dark areas. Whether this 
peculiar pattern reflects the juvenile pattern or whether such 
a condition is merely a part of the variation of saxidiceps is un- 
known. Certainly there is no doubt that this individual repre- 
sents this taxon ; the casque pattern is diagnostic. 



424 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY 

The paratypes vary scalewise in that there are between 18 
and 23 dorsals vertically, between 23 and 27 horizontally ; caudals 
range from 24 to 25, and fourth toe scales between 44 and 50. 

The dewlaps in two of the specimens of saxuliceps are still 
faintly pink. I assume that, despite the fact that all known 
saxuliceps are females, the dewlap coloration in males is pinkish. 
This coloration is quite different from the blue-green dewlap of 
haracoae to the east. 

COMPARISONS AND DISCUSSION 

With the description of five new races of Anolis equestris from 
Oriente, there are now nine subspecies from Cuba and another 
(hassleri) from the Isla de Pinos. Rather than inserting the 
comparisons between the named forms in their proper places in 
the descriptions, I am amassing them here for greater simplicity. 
Table 1 shows the range of scalation of the ten forms. 

Table 1 

Dorsal and caudal scale characteristics of ten populations of 

Anolis equestris. 

No, Dorsals Dorsals Caudals 



Subspecies 




(vertical) 


(horizontal) 


(horizon' 


luteogularis 


40 


14-22 


16-22 


19-28 


equestris 


42 


10-19 


10-17 


14-22 


thomasi 


17 


7-11 


7-12 


11-17 


noblei 


1 


20 


24 


22 


galeifer 


9 


17-24 


19-28 


21-26 


smallwoodi 


6 


18-21 


18-22 


23-26 


palardis 


3 


14-18 


16-24 


12-24 


haracoae 


6 


25-27 


23-33 


20-29 


saxuliceps 


4 


18-23 


21-27 


24-25 


hassleri 


4 


15-19 


16-21 


19-23 



The races smallwoodi, palardis, and in some cases haracoae 
and saxuliceps, all differ from thomasi in that they possess 
spotted dorsa ; thomtasi never has such a feature and is character- 
ized by white longitudinal streaking instead. Also thomasi is 
characterized by having exceptionally large scales, whereas all 
the new Oriente races are smaller scaled, with haracoae at the 
extreme. From A. e. equestris the Oriente races differ in dewlap 
color (haracoae), dorsal spotting (smallwoodi, palardis), and head 
and casque pattern (saxuliceps, nohlei, galeifer). In addition, 
haracoae at least is completely separable from the race equestris 



SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 



425 




426 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

on size of dorsals ; smallivoodi and saxuliceps are practically 
separable from equestris on this same character, although there 
is a small amount of overlap. 

From luteogularis, a dotted form in extreme western Cuba 
("with scattered specks of pale yellow on a green background," 
Schwartz, 1958: 5-6), the spotted Oriente races (smallwoodi, 
palardis) differ in much larger spots on the dorsum (in contrast 
to flecks which involve only part of a scale rather than several 
adjacent scales) ; haracoae differs in a blue-green rather than 
orange or j^ale yellow dewlap and much smaller dorsals ; nohlei, 
galeifer, saxuliceps differ in much more complex head patterns. 

The five new Oriente subspecies may be differentiated as fol- 
lows: 1) haracoae has small dorsals and a blue-green dewlap; 
2) smallwoodi is spotted dorsally and has the occipital region 
pale green; 3) palardis has heavy, almost reticulate, dorsal 
spotting without pale occiput and with a pale postorbital patch ; 
4) saxuliceps has a marbled or reticulate casque, spotted lores 
and labials, and lacks a postorbital blotch; 5) galeifer is un- 
spotted, with a pale postorbital blotch without a nuchal exten- 
sion. For detailed comparison of galeifer with noMei, see the 
discussion of the former form. Nohlei differs from the remaining 
Oriente races in having a pink dewlap (blue-green in haracoae) , 
having small dorsal dots (in contrast to heavy spotting in 
smallwoodi and palardis), having a mottled casque rather than 
a marbled or quasi-reticulate one (as in saxuliceps) , and from 
all Oriente races grouped together in having a nuchal extension 
of the pattern of the casque and occiput. 

It is obvious that there still remain many problems in the 
distribution of A. equestris in Oriente. We have no real data 
on the area of intergradation (or even the precise distributional 
relationships) of thomasi with any of the Oriente races. The 
distribution and variation of nohlei is unknown. The precise 
situation in the environs of the cities of Santiago de Cuba and 
Guantanamo is confused, due probably to improper labeling of 
specimens and lack of distinction between specimens taken in 
the cities and near them, especially in the foothills and mountains 
to the north. The identity of the race along the southern coast 
between Cabo Cruz and the Bahia de Santiago is indeterminate. 
Specimens are badly needed from the central portion of the 
mountain massif in the eastern part of the province, the single 
individual from near Felicidad and the one from Tmias give 
promise of increased complexities in this region. 



SCHWARTZ : ANOLIS EQUESTRIS IN ORIENTE 427 

SPECIMENS EXAMINED 

(All from Orientc I'l-dviiu-e, Cuba) 

Anolis cqiKstrls (hoinasi (10): (iibara, :} (A. Schwartz col- 
lection 285) ; Bancs, 4 (AS 28Gj ; Los Angeles, 5 nii. E Banes, 
2 (MCZ 25153-54); Cabo Cruz, 1 (AMNH 83632). 

Anolis c. nohlci (1) : Sierra de Nipe (MCZ 26653). 

Anolis c. (jalcifer (9) : nr. Buey Arriba, SW Bayanio, 2 (MCZ 
59325-26) ; nr. Loma del Gate, 1 (MBZII 142) ; Las Mercedes, 
27 km S Yara, 1 (AMXII 83627) ; mountains near Guisa, 4 
(HM 5261) ; "Oriente," 1 (IIM 5936). Guama, 1 (USNM 29784) 
is questionably associated with galcifer. 

Anolis e. sinalhroodi (10) : 9.4 mi. W Laguna de Baconao, 1 
(AMNH 89525); Laguna de Baconao, 5 (AMNH 89526-30); 
Hongolosongo, 1 (MBZH 260) ; Playa Juragua, 1 (AMNH 
89532) ; Santiago de Cuba, 1 (MCZ 6!)24) ; 4 km N Santiago de 
Cuba, 1 (AMNPI 89531). 

Anolis e. palardis (3) : Rio Yateras, 5 mi. N river mouth, 1 
(CM 333200); Baitiquiri, 1 (MCZ 42551); Guantanamo (U.S. 
Naval Base), 1 (MCZ 68921). 

Anolis e. baracoiK (6): Joar, Baracoa, 1 (MCZ 47050); Ba- 
racoa, 5 (AMNH 83628-30; MCZ 57404; MCZ 42520). 

Anolis e. saxuliccps (4): Moa, 3 (ini 5376(2); HM 5374); 
ca. 7 km E Moa, 1 (MCZ 59324). 

Anolis cqucstris inccrtae sedis: Santiago de Cuba (USNM 
58855) ; coast south Pico Turquino (MCZ 42480) ; nr. Guan- 
tanamo (MCZ 8977); Guantanamo (USNM 58057; MCZ 
57928) ; Imias (MCZ 42552) ; 8 mi. NE Felicidad (AMNH 
83631). 

LITERATURE CITED 

Barbour, Thomas, and Benjamin Shreve 

1935. Notes on Cuban ancles. Occ. Papers Boston Soc. Nat. Hist., 
8:249-253. 
Hardy, Jerry D., Jr. 

1958. A new lizard of the genus Lciocrplialus from Cuba (Squaniata: 
Iguanidae). Jour. Washington Acad. Sci., 48(9) :294-300, 5 tigs. 
MAEitz, A., AND M. Rea Paul 

1950. A dictionary of color. New York, McGraw-Hill Book Co., pp. 
i-vii, 1-23, 137-208, 56 pis. 

Marrero, Levi 

1951. Geografia de Cuba. Habaua, Alfa, pp. i-xvi, 1-736, 478 figs. 



428 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Schwartz, Albert 

1958. A new subspecies of Anolis equestris from eastern Cuba. Herpe- 

tologJea, 14(1): 1-7, 1 fig. 
1960. Variation in tlie Cuban lizard Leioceplialus raviceps Cope. Proe. 
Biol. Soc. Washington, 73:67-82, 10 figs. 
Stejneger, Leonhard 

1917. Cuban amphibians and reptiles collected for the United States 
National Museum from 1899 to 1902. Proc. U.S. Nat. Mus., 
53:259-291, 128 figs. 



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SCIIWART/: AXOI.IS IX^I'KSTHIS IX OHIKXTE 




Bulletin of the Museum of Comparative Zoology 
HARVARD UNIVERSITY 

Vol. 131, No. 13 



THE LYNX SPIDERS OF NORTH AMERICA, 
NORTH OF MEXICO (ARANEAE : OXYOPIDAE) 

Bv Allen R. Brady 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

September 30, 1964 



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Bulletin of the Museum of Comparative Zoology 

HARVARD UNIVERSITY 
Vol. 131, No. 13 



THE LYNX SPIDERS OF NORTH AMERICA, 
NORTH OF MEXICO (ARANEAE : OXYOPIDAE) 

By Allen R. Brady 



CAMBRIDGE, MASS., U.S.A. 
PRINTED FOR THE MUSEUM 

September, 1964 



Bull. Mus. Conip. Zool., Ihiivaid I'liiv., 131 (13) :429-r)18 Septomber 19()4. 

No. 13. — THE LYNX SPIDERS OF NORTH AMERICA, 
NORTH OF MEXICO {ARANEAE: OXYOI'JDAE)^ 

By 
Allen R. Brady 

CONTENTS 

Page 

Introduction i'.VI 

Genera of Oxyopidae 433 

Superfamily Lycosoidea 435 

Biology of the Oxyopidae 436 

Acknowledgments 438 

Walckenaerian Names 439 

Methods 442 

Taxonomic Section 

Oxyopidae Thorell 444 

Key to Genera 446 

Oxyopes Latreille 447 

Species Groups of Oxyopes 448 

Key to Species of Oxyopes — Males 452 

Key to Species of Oxyopes — Females 453 

Oxyopes acleistus Chamberlin 454 

Oxyopes aureus sp. n 457 

Oxyopes aglossus Chamberlin 461 

Oxyopes occidens sp. n 464 

Oxyopes apollo sp. n 467 

Oxyopes floridanus sp. n 469 

Oxyopes tridens sp. n 472 

Oxyopes pardus sp. n 474 

Oxyopes lynx sp. n. 475 

Oxyopes felinus sp. n 476 

Oxyopes salticu^ Hentz 478 

Oxyopes . scalaris Hentz 484 

Hamataliwa Keyserling 496 

Eamataliwa helia (Chamberlin) 497 

Hamataliwa unca sp. n. 499 

Hamataliiva grisea Keyserling 501 

Feucetia Thorell 505 

Peucetia viridans (Hentz) 506 

Peucetia longipalpis F.O.P.-Cambridge 512 

List of Collectors 515 

Literature Cited 516 



1 This study was presented to the Department of Biolopy at Harvard Univer- 
sity in partial fulfillment of the requirements for the degree of Doctor of Phi- 
losophy. 



432 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 

INTRODUCTION 

The family Oxyopidae comprises 371- described species dis- 
tributed chiefly throughout the tropical and subtropical regions 
of the world. This investigation is concerned with the evolution- 
ary relationships and distribution of those species occurring 
north of Mexico. Of the 17 species involved, most occur only in 
the southern United States, but several occur over wide areas 
in the temperate and colder regions of North America. Oxyopcs 
salticus and 0. scalaris are found from coast to coast, and 0. 
scalaris ranges from British Columbia and Labrador to northern 
Mexico. It is of interest that several widely distributed species 
of Oxyopes are also found in the temperate regions of Europe 
and Asia. 

Large collections from Central America, Mexico and the West 
Indies were examined to determine the range of the oxyopids 
found north of Mexico. This study also illuminated the rela- 
tionship between the Mexican, Central American and West 
Indian faunas and that of temperate North America. A pre- 
liminary examination of the species occurring in the Neotropical 
region reveals that the number of described species of Oxyopidae 
will almost certainly be doubled when the tropical regions have 
been fully investigated. 

The oxyopid types of 0. Pickard-Cambridge and F. 0. Pickard- 
Cambridge (1894, 1902), deposited in the British Museum (Nat- 
ural History), were examined as a part of this study. Their 
examination provided the information that determined whether 
or not the names used by 0. P.- and F. 0. P.-Cambridge should 
be applied to any of the oxyopids found north of Mexico. 

C. A. Walckenaer (1838, 1841) in his "Histoire Naturelle des 
Insects" described six species of Oxyopidae from the Georgia 
region of the United States. These descriptions were based on 
the drawings in the unique manuscript of John Abbot (1792). 
The drawings are expertly done and adequate for identification 
of some species. However, it is often difficult or impossible to 
decide on the basis of color pattern what species is figured, and 
only if the specimen were at hand, or the genitalia figured, could 
one make an accurate decision. Walckenaer had few specimens 
to guide him and frequently placed spiders in the wrong family, 
e.g. Sphasus vittatus Walckenaer is obviously a clubionid, not 
an oxyopid. The Abbot manuscript, also deposited in the British 

2 Based on latest records in the Zoological Record, vol. 98, sect. 12, 1961. 



BRADY : LYNX SPIDERS 01-^ NORTH AMERICA 433 

Museum (Natural History), was examined and the drawings 
photographed. These colored photographs are deposited in the 
Museum of Comparative Zoology. The names pertaining to the 
Oxyopidae that AValekonaer applied to the drawings of Abbot 
and Bosc (1800) are discussed below. 

GENERA OP OXYOPIDAE 

Eleven genera are placed in the O.xyopidae at present. The 
number of species and the geographical distribution of species 
are listed in Table I. This list, based on that of Roewer (1954), 
includes the species described through 1961. Of the eleven genera 
listed, I have examined representatives of five {Oxyopes, Hama- 
taliwa, Peucetia, Oxyopeidon, and Tapinillus) m collections 
from the entire world, with particular attention to those species 
occurring in North America, Mexico, Central America and the 
"West Indies. From this study I conclude that Oxyopeidon must 
be sjaionymized with Hamataliwa, as Bryant (1948) has already 
pointed out. The genus Oxyopeidon was differentiated from 
Hamataliwa by the position of the anterior median eyes (AME) 
and by the spacing of the posterior median eyes (PME). Not 
only do such differences occur between closely related species, 
but these differences in eye arrangement may occur between 
sexes of the same species. The genus Hamataliwa is, therefore, 
redefined. From the descriptions in the literature it is apparent 
that the genus Lacsfrygones Urquhart is not an an oxyopid and 
should be removed from the Oxyopidae, as has been done by 
Bryant (1933) and Forster (1955). 

The descriptions of Hostus paroculus Simon and Pseudohostus 
squamosus Rainbow, the type species of monotypic genera, place 
them well wathin the range of variation found among species of 
Oxyopes. Simon (1898) places Meguilla trxmcaia Thorell, an- 
other type species, in the genus Hamataliwa where it probably 
belongs. Remaining in the family Oxyopidae, then, are six valid 
genera: Oxyopes, Peucetia, Hamataliwa, Tapinillus, Schaenios- 
celes, and Tapponia. Laestrygones should be removed from the 
Oxyopidae. Oxyopeidon most certainly and Meguilla probably 
should be synonymizecl with Hamataliwa. The monotypic genera 
Hostns and Pseudohostus are probably synonyms of Oxyopes. 

The structure of the genitalia, particularly of the male palpus, 
serves as an accurate indicator of generic as well as specific rela- 
tionships. The above conclusions regarding the placement of 



434 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

genera were based on characters of the genitalia together with 
general body form and color, and the relative length of the legs. 
The arrangement of the eyes and the width of the various eye 
rows prove useful in separating some genera (Tables II and 
III), but they were not used as the primary basis for establishing 
genera, as in the past. The examination of oxyopids from all 
parts of the world has indicated that the genus Hamataliwa, 

Table I 

GENERA OF OXYOPIDAE 

Genus Geographical Number 

tI^££rS_p_e_c_!jjJ Author _D.'JJli^L'fi?_ °f APli'AL 

Ui'JM.'i'iLwS Keyserling, 1887 Neotropical 14 

(gHsea) 

H^JiJil Simon, 1898 Madagascar I 

<£5L°5.y.L4A} 

Ljjestr^iones^ Urquhart, 1-894 New Zealand and 3 

(ii^'JLlTJj) Subantarctic Isls. 

MAM-UI?. Thorell, 1897 Indochina I 

(truncal a) 

Ojcj^jjidon 0. P. -Cambridge, 1894 Ethiopian 5 

rpufum) Neotropical 24 

Ojcy^jej Latreille, 1804 Palaearctic 19 

(heteroDhthalmus) Ethiopian 93 

^ Oriental 45 

Malay Peninsula 

to New Guinea I 

Australian 23 

Neotropical 47 

Nearctic 1 1 

E3J^S3lL%. Thorell, 1869 Palaearctic 5 

(viridis) Ethiopian 25 

Oriental 4 

Australian 2 

Neotropical 22 
Neotropical and 

Nearctic I 

fj^i)i.dj)ji^jius Rainbow, 1915 Australian I 

(squam_o_sjj_s) 

SiJ?jei>ioi££iLS_ Simon, 1898 Neotropical 7 

(elegans) 

Jj^inLL'jJ Simon, 1898 Neotropical 4 

(j_on|_i_p_e_s) 

iJJJ^jJa Simon, 1885 Malay Peninsula 

(micans_) and East Indies [^3 

Total 37 1 

Based on Roewer (1954) with additions from the Zoological Record through 
vol. 98, sect. 12, 1961. 



BRADY: LYNX SPIDERS OF NORTH AMERICA 435 

when propcfly diagnosed, -will undoubtedly prove to have a 
distribution comparable to that of Oxyopes and Peiicetia. It is 
also possible that the large genus Oxyopes may be found to con- 
sist of several distinct groups each deserving generic status. 

SUPERFAMILV LVCOSOIDEA 

The oxyopids are grouped with the Agelenidae, Lycosidae, 
Pisauridae and Senoculidae in the superfamily Lycosoidea by 
most araneologists. The Oxyoi)idae, in common with most mem- 
bers of these families, po.ssess: eight eyes, three tarsal claws 
without claw tufts, three pairs of spinnerets, two lung books 
opening at the corners of the epigastric furrow, a single tracheal 
opening in front of the anterior spinnerets, and a rather large 
colulus. In addition, all members of this superfamily, with the 
exception of the Agelenidae, have the trochanters notched. The 
trochanters of pisaurids and lycosids are more deeply notched 
than in oxj^opids, while most agelenids do not have notches, 
although some do, according to V. D. Roth (per. comm.). 

The lynx spiders are a highly specialized group of the Lyco- 
soidea ; that is, they are probably more unlike the ancestral stock 
than any other family in this complex. The agelenids, lycosids 
and pisaurids are linked by intermediate forms, whereas it is 
difficult to find intermediates between the oxyopids and any of 
these three families. I am not familiar with the spiders of the 
family Senoculidae except by examination of preserved speci- 
mens. They also appear to be a very distinct group of the Lyco- 
soidea, but some authors place them near the Oxyopidae (Simon, 
1898). On the basis of morphological characters and reported 
habits, I can see no close affinities between the Oxyopidae and 
Senoculidae. Although the oxyopids form a distinct line of evolu- 
tion, their affinities unmistakably lie with the lycosoids. 

Unlike most other representatives of the families of the Lyco- 
soidea, the Oxyopidae are most active during the day. Many 
species are found running swiftly or jumping with great agility 
among low shrubs and herbs. The North American oxyopids are 
easily recognized in the field by the presence of numerous large 
erect spines on the legs (Figs. 4, 49, 50, 121, 138) and by their 
quick darting movements and sudden leaps. The posterior legs 
are well developed, concomitant with their jumping ability. The 
habits of these spiders and their relatively keen eyesight have 
earned for them the name lynx spiders. 

Under the microscope one can readilj^ identify the lynx spiders 



436 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

by their peculiar hexagonal eye arrangement (Figs. 1-3, 108-111, 
136, 137). The eye arrangement and the spines on the legs most 
readily separate the oxyopids from all other families of spiders. 
In addition, the lynx spider fixes its egg ease to a twig or leaf 
and enmeshes it with a netAvork of silk, or suspends it from a small 
limb or branch with a guy-line. The female always stands guard 
over the egg case until the young emerge. The nearest counter- 
part to this type of maternal behavior is found in some pisaurids 
that construct a so-called nursery web and remain near the egg 
case until the young spiderlings appear. In addition to this 
behavioral similarity, some tropical pisaurids, such as Thanatid- 
ius, with long thin legs and many spines, resemble Peucctia and 
Tapinillus in general structure. Thanatidius also inhabits tall 
grass and herbaceous vegetation as do many of the oxyopids. For 
these reasons I think that the nearest living relatives of the lynx 
spiders are among the Pisauridae. 

BIOLOGY OF THE OXYOPIDAE 

The Oxyopidae are diurnal hunting spiders. Most of the lynx 
spiders move actively about in search of prey. However, they 
often pause and assume a characteristic prey-catching posture 
to await their victim. Hamataliwa lies very still waiting in 
ambush for its prey, as do many crab spiders. The great major- 
ity of oxyopids live in tall grass, low shrubs and herbaceous 
vegetation. A few {Hamataliwa) are evidently arboreal in habits 
and some appear to run over the bare ground. 

That relatively little is known concerning the biology of the 
Oxyopidae is due chiefly to the difficulty of observing these 
spiders in the field. Probably 95 per cent of the oxyopids col- 
lected are taken by sweeping; thus they are observed only when 
they appear in the sweep-net. Judging from their local abun- 
dance, the lynx spiders are among the major predators of insects 
occurring in low shrubs and herbaceous vegetation. Very few 
observations have been made on the feeding habits of the lynx 
spiders. Recent investigations by W. H. Whitcomb and asso- 
ciates (1963) have disclosed that the lynx spiders are important 
predators of crop-damaging insects. Oxyopes salticus, one of the 
most common spiders of the cotton fields in Arkansas, has been 
reported as the chief predator of the cotton boll worm. Peucctia 
viridans is also an important predator on insect pests of cotton 
fields. Although several species of Oxyopes have been recovered 
from the nest of the mud-dauber, Sccliphron cocmentarium, these 



BRADY : LYNX SPIDERS OF NORTH AMERICA 437 

ox^-opids do not constitute a large part of the prey of this wasp. 

Among thousands of specimens of oxyopids examined during 
this investigation only very rarely was an egg case found. In 
several hundred vials containing Oxijopcs salticus, only two egg 
cases were discovered. These were roughly spherical and about 
3.5 mm in diameter; one contained 55 spiderlings and the other 
18-20 eggs, each a little less than 1 mm in diameter. The extreme 
rarity of oxyopid egg cases is probably due to the method of col- 
lecting the.se spiders. In sweeping the vegetation the spiders 
are dislodged, but the egg cases, firmly attached to the vegeta- 
tion, are not. Egg cases of Peucctia viridans, a much larger and 
more conspicuous lynx spider than Oxyopcs salticus, are en- 
countered more frequently. These egg sacs are rounded, from 
12-25 mm in diameter, flattened on one side, and, except in the 
Southwest, have pointed projections on the surface. The eggs 
are about 1.5 mm in diameter. The number of eggs in an egg 
case is dependent on many factors and for that reason is ex- 
tremely variable. The contents of nine egg cases of Peucetia 
viridans ranged from 197 to 602 eggs. Often the chief factor in 
determining the number of eggs deposited is probably the size 
of the individual spider, larger spiders depositing more eggs than 
smaller ones of the same species. Peucctia viridans, the largest 
North American lynx spider, produces many more eggs than 
the much smaller species of Oxyopes. 

The North American lynx spiders evidently have one genera- 
tion per j^ear and probably construct only one egg case. The 
adults of several species of Oxyopcs appear first in late spring 
(May and early June) and are most abundant in July and Au- 
gust. Adult Peucetia appear later, in late July and August, 
and are most abundant in August and September. In general 
there seems to be a correlation between the size of the species 
and its date of maturity. Smaller species of Oxyopcs ajipear as 
adults in May, while Peucctia reaches maturitj^ in July. From 
the limited information and observations made, it appears that 
most lynx spiders over-winter in the egg case as embryos or first 
instar spiderlings ; however, in the extreme southern portions of 
their ranges there are probably several generations per year and 
adults may be found at any season. 

Although very few observations have been made of oxyopids 
ballooning, they undou])tedly employ this means of dispersal. 
Gliek (1939), in his study of the distribution of in.sects, spiders 
and mites in the air, reported 21 specimens of Oxyopcs and one 



438 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Peucetia taken from 200-3,000 feet (70-1000 m), most nearer the 
lower elevation. These 22 specimens were collected from August, 
1926 to October, 1931, in the air over Tallulah, Louisiana. 

Suzuki (1952) reported that the chromosomes of five species 
of Oxyopes had been studied. All five species had 11 chromo- 
somes in the haploid state and an XO sex-determining mechan- 
ism. The XO-mechanism of the male (2N = 21), as well as the 
number of chromosomes, was similar to that found in the sub- 
family Misumeninae of the family Thomisidae. In one species of 
Peucetia studied by Suzuki there were 13 autosomes and 2 
X-chromosomes of different size. The male of Peucetia (2N = 28) 
was similar in these characters to many Philodromus species, as 
well as to most species of Lycosidae that were studied. 

Since the oxyopids are diurnal and possess relatively keen 
sight, their courtship behavior probably plays an important role 
as a primary isolating mechanism. Mating in the Oxyopidae, 
however, has been observed onlj^ rarely, and the comparative 
aspects of this behavior are unknown. Gerhardt (1928, 1933) 
has observed courtship behavior in two European lynx spiders, 
Oxyopes ramosus and Oxyopes heterophthalmus. Although males 
of 0. heterophthalmus readily displayed, Gerhardt (1933) suc- 
ceeded in mating these spiders in captivity only once. Copula- 
tion is in the modified running-spider position (see Kaston, 1948, 
fig. 2006). The male approaches the female from in front and 
climbs on top. The venter of the female is slightly turned to- 
ward one side, allowing insertion of the palpus. In 0. heteroph- 
thalmus the large tibial process (Fig. 101) of the male is 
used to orient the palpus. The male swings itself around 180° 
so that its body is in the same direction as the female's. No 
observations of the mating behavior of North American oxyopids 
have been recorded. A comparison of courtship behavior in the 
lynx spiders would, undoubtedly, prove most informative. 

ACKNOWLEDGMENTS 

I am greatly indebted to Dr. H. W. Levi of the Museum of 
Comparative Zoology, who, by his helpful advice, useful sug- 
gestions and constant encouragement, has made the preparation 
of this paper a much easier task. The collections of the Museum 
of Comparative Zoology and the library of this institution were 
invaluable to me during this investigation. I wish to thank 
sincerely Dr. W. J. Gertsch who placed the very large collec- 
tions of the American Museum of Natural History at my dis- 
posal, thus making possible a tlioi'ougli and comi)lete analysis of 



HKADY : LYNX SPIDERS OF NORTH AMERICA 439 

many species. Dr. Gertscli was kind enough to include specimens 
that he liad previously recognized as new species and they are 
described in this study -with his permission. 

During the course of this investigation I spent several weeks 
at the British Museum (Natural History) where I examined 
the types of 0. P.- and F. 0. P.-Cambridge. Photographs were 
also made of the plates of John Abbot (1792) which are de- 
posited in the library of that museum. I am grateful to Dr. G. 
Owen Evans, Mr. Douglas Clark and Mr. Keith Hyatt for mak- 
ing my visit to the British Museum (Natural History) a most 
pleasant and profitable one. Professor M. Vachon supplied 
photographs of the Bosc plates, which are kept in the library of 
the Museum National d'Histoire Naturelle, Paris. 

A travel grant provided by the Evolutionary Biology Com- 
mittee of the Biology Department of Harvard University made 
the trip to the British Museum (Natural History) possible. I 
wish to thank the Biology Department of Harvard University 
also for financial aid on several collecting trips into the southern 
United States. 

Collections of Mrs. D. L. Frizzell (Dr. H. Exline) and Mr. 
J. A. Beatty aided me in this study considerably and 1 appre- 
ciate their loans in behalf of this investigation. 

To the following persons and their respective institutions I 
wish to express my thanks for supplying regional collections 
that provided a more complete picture of the geographical dis- 
tribution of certain species: Dr. H. K. Wallace, University of 
Florida ; Mr. Vincent D. Roth, Southwestern Research Station ; 
Dr. F. G. Werner, University of Arizona ; Dr. George Byers, 
University of Kansas; Miss Beatrice Vogel, University of Colo- 
rado Museum; and Dr. C. A. Triplehorn, Ohio State University. 

A special debt of gratitude is owed to jMrs. Lorna Levi for 
critically examining and editing the rough draft of this manu- 
script. Miss Susan Koelle mapped the species distributions and 
constructed the Dice-Leraas diagrams. National Institutes of 
Health grant AI-01944 helped defray some expenses involved 
in this study. 

WALCKENAERIAN NAMES 

Walckenaer (1838) in Volume I of "Histoire Naturelle des 
Insectes Apteres, ' ' named and described, from the Georgia region 
of North America, three new species of oxyopids in the genus 
Sphasus, a genus since synonymized with Oxyopes. In addition. 



440 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Walckenaer (1838, 1841) named and described three species of 
Clastes, placed in the family Sparassidae, from the Georgia re- 
gion. The six names that concern us in this paper were applied 
to the original drawings of the unique manuscript of John Ab- 
bot (1792). Since they were rediscovered in the British Museum 
(Natural History) by McCook (1888), the Abbot drawings 
have been considered the types of the Walckenaerian names 
by most North American araneologists. They had been used 
with some reservation, however, until Chamberlin and Ivie 
(1944) attempted "to determine, as far as possible from avail- 
able evidence, the proper application of the names based by 
Walckenaer upon Abbot's drawings of the spiders of Georgia." 
In their paper, Chamberlin and Ivie placed in synonymy manj- 
well-established names that had been used for North American 
spiders. Involved are 282 names that Walckenaer applied to 
drawings made by Abbot. These must be considered when re- 
vising almost any family of North American spiders. I agree 
with Levi and Levi (1961) that these names can only be given 
proper treatment by the investigator who has made a thorough 
and intensive taxonomic study of the spider genera in question. 
Unfortunately, Walckenaer made many mistakes in the iden- 
tification of the Abbot drawings, and Chamberlin and Ivie have 
made some errors in their all-inclusive determinations of the 
Abbot drawings. A few of these errors are pointed out by Levi 
and Levi (1961) and this investigation has disclosed several 
more. 

Of the three species of Sphas^(^ (= Oxyopes) described by 
Walckenaer, only one appears to be an oxyopid. The disposition 
of the three is as follows : 

Sphasus arcuatus Walckenaer (Abbot numbers 322, 323) is 
not an Oxyopes, as it was designated ])y Chambei-lin and Ivie 
(1944), but probably belongs in the theridiid genus SpinfJiarus. 
There are no spines on the legs of this spider as figured by Ab- 
bot, an important characteristic of all oxyopids; the color pat- 
tern is not like that of any oxyopid that I have seen, but is sim- 
ilar to that of Spintha7-i(s fiavidus (Hentz) ; and the eye ar- 
rangement, a very important character, is not as in the Oxyo- 
pidae. Body form, coloration, and relative length of the legs 
is like that in Spintharus fiavidus (Hentz). 

Sphasus vittatus Walckenaer (Abbot number 369) is obvi- 
ously not an oxyopid. Tliis spider was placed in the genus 
Castianeira of the family Clubionidae by Chamberlin and Ivie 



BRADY : LYNX SPIDERS OF NORTH AMERICA 441 

(1944). Judging from the original figure of Abbot, that is 
where it probably belongs. However, no species is known to 
which the description and figure can be applied. 

Sphasus Janccolatus AValckenaer (Abbot number 42) is an 
oxyopid. Chaml)erlin and Ivie (1944) described a species of 
Oxijopcs under this name. Although they designated a neotype, 
it has no validity since the holotype, namely Abbot's figure 42, 
is still extant. The neotype has since been misplaced or lost 
and was not available for examination ; thus it cannot be com- 
pared with Abbot's original figure. We have only the figure of 
Abbot to guide us, and the dorsal view, showing the color pat- 
tern and eye arrangement, is not sufficient for diagnosis in this 
case. Tlie colored drawing of AbI)ot, much like that of Oxyopes 
scalaris Hentz, may also be 0. aglossus Chamberlin or 0. ac- 
leistus Chamberlin. Chamberlin and Ivie (1944), however, con- 
sidered these three species distinct from 0. lanceolatua. Oxyopes 
lanceolatus has been perpetuated in the catalogues of Marx 
(1890), Petrunkevitch (1911), Roewer (1954), and Bonnet 
(1958). It has not otherwise been used in the literature except 
by Chamberlin and Ivie (1944). Since the name 0. lanceolatus 
might be applied to at least four distinct species, I think that 
it is best considered a nomen duhium. 

Three names proposed by AValckenaer (1838, 1841), Clastes 
ahboti (Abbot number 401), C. roseiis (Abbot number 411), 
and C. viridis (Abbot number 406), were recognized as the same 
species by Chamberlin and Ivie (1944). They applied the name 
Peucetia ahhoti (Walckenaer) to this large green lynx spider 
of the southeastern United States. The name Peucetia viridans 
(Hentz) had been used for this species for 100 years prior to 
the change by Chamberlin and Ivie (1944). Hentz 's name ac- 
tually has priority, having been used first in 1832, six years 
before "Walckenaer 's publication. 

Walckenaer previously (1805) described and named another 
oxyopid for a drawing appearing in the unique manuscript of 
Bosc (1800) on the spiders of the Carolinas. This manu- 
script is deposited in the Paris Museum. The drawing (Bosc, 
pi. 4, fig. 1) was designated Aranea fossana by Bosc (1800), 
and its description was published by Walckenaer (1805) who 
called it SpJiasus fossanus. Judging by Bosc's drawing and the 
description of Walckenaer, this species is Peucetia viridans 
(Hentz). Oxyopa fossana was listed by Simon (1864) and the 
name Oxyopes fossanus has been perpetuated in the catalogues 



442 BULLETIN : MUSEUM OP COMPARATIVE ZOOLOGY 

of Marx (1890), Petriinkevitch (1911), Roewer (1954) and Bon- 
net (1958). The name has never been applied or used in any 
manner to designate a species of Oxyopidae. It is here con- 
sidered a nomen ohlitum. 

In summary, the following' dispositions have been made of 
the Walckenaerian names: SpJiasus arcuatus is probably Spin- 
tharus flavidus Hentz ; Sphasus vittatus is probably a Castian- 
eira; Sphasus lanceolatiis is a species of Oxyopes, but there is 
some doubt as to which one; Clastes ahhoti, C. roseus, and C. 
virklis are Peucetia viridans (Hentz). Spliasns fossanus is 
probably Peucetia viridans (Hentz), and is considered a nomen 
ohlitum. 

METHODS 

Measurements. Two sets of oculars with accompanying grids 
were used in combination with low and high power objectives 
for making measurements. The higher power combination was 
used in measuring the width of the eye rows and was determined 
to be accurate to 0.0125 mm or one-tenth unit of the micrometer 
grid. The lower power combination was used to measure the 
body dimensions and leg lengths and was determined to be ac- 
curate to 0.1 mm or one-tenth unit of the micrometer grid. A 
measurement when retaken was nearly always read within one 
unit of the original measurement with either of the above mi- 
crometer grids, e.g. an original measurement of 7.5 micrometer 
units when retaken yielded 7.4-7.6 units. In all cases the great- 
est dimension of the structure was recorded, e.g. patella-tibia 
length was measured as the greatest distance from a line tangent 
to the most proximal part of the patella to a line tangent to the 
most distal part of the tibia. All available specimens of sparsely 
collected species were measured and a set of 30 specimens of 
each sex was measured for those species abundantly repre- 
sented in collections. 

A series of 15 measurements involving various components 
of the spider was made for each specimen. The range and mean 
of the total length for each species is given in its description 
and the relative length of the legs is also given. Other diag- 
nostic measurements are recorded for Oxyopes in Table II and 
for Hamataliwa and Peucetia in Table III. The segments of 
leg I were measured from the prolateral aspect, as was patella- 
tibia II. The patellae-tibiae of legs III and IV were measured 
from their retrolateral aspect. 



BRADY : LYNX SPIDERS OF NORTH AMERICA 443 

Figures and color descriptions. The color deserij)tions and 
illustrations are based on fresh alcoholic specimens in most cases 
and represent these species as they appear in nature. Tlie genus 
Peucctia is an exception. Tliis spider is bright green in life, 
but the color Avashes out rapidly in alcohol. Therefore, an at- 
tempt was made to describe both preserved and living animals 
of Peucetia. 

Color descriptions and illustrations Avere made under low 
power (15X) of a dissecting microscope, with the spider illnm- 
inated by a microscope lamp. The well-marked specimens are 
those in which the hairs forming the color pattern have not been 
rubbed off. Where variation is great, the color pattern or pat- 
terns representative of the greatest number of specimens is 
described, with significant differences noted. Well-preserved 
alcoholic specimens of Oxyopes and Hamataliiva are very sim- 
ilar in coloration to the living spider. The most fre(iuent dif- 
ferences are caused by shrinking in alcohol, Avhich disrupts the 
pattern on the abdomen, and rubbing off of the spatulate ap- 
pressed hairs that make up much of the color pattern in these 
two genera. 

For each species the face view as well as the dorsal view of 
a male and female (Avhen available) was drawn, with additional 
drawings to indicate variation. At least two drawings of the 
female genitalia Avere made for each species : a A^entral external 
view of the epigynum after all the hair had been removed (often 
revealing some internal structure through the integument), and 
a dorsal internal vicAV Avith the separated genitalia submerged in 
clove oil for clearing. The female genitalia of all species of 
Oxyopes and IlomataUwa are draAvn to the same scale. Peucetia 
is draAvn on a smaller scale. The scales are indicated on the 
plates. Two views of the male palpi Avere draAvn for each species : 
a ventral a'Icav and a retrolateral view. The left palpi of the 
males were drawn after gently scraping them free of hair to 
reveal the palpal sclerites and the tibial and patellar apophyses. 
No attempt Avas made to indicate hirsuteness or spination in 
these drawings. All palpi of Oxyopes and Hamataliwa are 
draAvn to the same scale. Peucetia palpi are draAvn on a smaller 
scale. 

That area referred to as the face is, in oxyopids, the anterior 
vertical plane of the head as seen from in front (Figs. 1 and 5). 
It comprises the frontal aspect of the carapace and includes 
the front of the chelicerae. 



444 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Records. Complete records for all the specimens examined 
during this investigation are listed in the Doctoral Dissertation. 
Copies of the dissertation are deposited in the library of the 
Biological Laboratories and in Widener Library, Harvard Uni- 
versity. Locality records are listed geographically by states in 
a sequence from north to south and from east to west. Coun- 
ties are listed alphabetically under states, cities and towns 
alphabetically under counties. Counties only are listed when a 
particular species is abundantly represented and obviously 
common in a given geographic area. For less well collected 
species full information is provided. The number of specimens 
collected at each locality is indicated, with thq lower case "o" 
representing immature specimens in the same manner that the 
$ and 9 signs represent the mature sexes. Collectors' initials, 
following the localities, are listed in a separate index at the rear 
of this paper. Occasional collectors are given by name. 

TAXONOMIC SECTION 

Family OXYOPIDAE Thorell 

Oxyopidae Thorell, 1870, Nova Aeta, Eeg. Soe. Sci. Uppsala, Stockholm, 
7(3):188, 196. Type-genus Oxyopes^ Latreille, 1804. 

Characteristics. Eyes : Anterior row recurved, except in some 
Hamataliwa. Anterior median eyes (AME) smallest, much 
smaller than the anterior lateral eyes (ALE). Posterior row 
procurved {exce-pt in Tapiiiillus) . Posterior median eyes (PME) 
equal in size to posterior lateral eyes (PLB) ; both pairs larger 
than the AME, but smaller than the ALE, which are the largest 
(Figs. 1-3, 108-111, 136, 137). The AME row is much the 
smallest in width, the ALE row is always larger than the AME 
row, and subequal to the PME row, except in Peucetia, Tapinil- 
lus, and some Hamataliwa (compare Table II with Table III). 
The PLE row is the widest. 

The chelicerae are very long and tapering at the distal end, 
and the fangs are short. The base of the fang occupies most 
of the distal end of the chelicera. The cheliceral margins are 
short and armed with one tooth on each side of the anterior and 
posterior margins (Oxyopes and Hamataliwa) or without teeth 
{Peucetia and Tapinillus) . The boss on the anterior lateral 



3 According to Thorell (18(59) Oi^yopvs is derived from the Greelj and means 
sharp-eyed. 



BRADY: LYNX SPIDERS OF NORTH AMERICA 445 

face of tlie cliolicera is not so proiuiuciit as in agolenitls, pisaur- 
ids and lycosids. Tlie articular sockets of the chelicerae at 
the lower marfjins of the face are heavily selerotized and dai-kly 
j)i<inieiited. 

The cephalothorax is variable in shai)e. The drawinj^s of 
Oxyopes (Figs. 2, 3, 6), Pcucetia (Figs. 137, 142) and Ilama- 
taliwa (Figs. 109, 111, 114) indicate the form of the carapace 
from above. Oxyopes has the carapace high and convex, slop- 
ing sharply at the thoracic declivity and at the sides. The face 
is almost vertical. Ilamataliwa has the carapace even higher 
in many species, more sharply vertical at the thoracic declivity 
and sides, but with the face sometimes sloping more gradually 
and not vertical, as illustrated in Figures 109 and 111. Pcucetia 
has the carapace more flattened, not as convex as in Oxyopes, 
and tapering gradually to the sides. This genus is more lycosid 
in appearance than the others. The thoracic groove is ]:)rom- 
inent in Peucefia, and not deep, but also usually well marked 
in Oxyopes and Hamataliwa. 

The labium is always longer than wide and the endites exceed 
greatly its length and converge in front of it (Figs. 10 and 139). 
The sternum is roughly heart-shaped or shield-shaped (Figs. ]0 
and 139), and tapers behind to a thin projection between the 
posterior coxae. 

The abdomen is elongate, widest immediately behind the base 
and more or less sharply tapering behind. In Oxyopes it is 
ovoid or elliptical and tapers sharply behind ; in Hamataliwa, 
truncate near the base and again tapering to a point ; but in 
Pcucetia the abdomen is somewhat cylindrical, more elongate 
than in the two preceding genera, and tapering more gradually 
to the spinnerets. 

The abdomen is connected to the cephalothorax by a short 
pedicle, often visible from above. The superior lorum, usually 
visible from above, is composed of a single undivided sclerite. 
It is divided into two sclerites in the Lycosidae and Pisauridae. 

The six spinnerets are terminal. The cylindrical anterior 
spinnerets consist of a relatively large basal segment and an 
abbreviated, almost ring-like, apical segment. The posterior 
spinnerets, also two-segmented, are about the same length as the 
anterior, but more slender in diameter, with the apical segment 
shorter than the basal one, but larger than the distal segment 
of the anterior spinnerets. The tiny middle spinnerets are well 
hidden in their position between and slightly forward of the 



446 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

posterior ones. The second segment of the posterior spinnerets 
is tapered on its inner surface where it is supplied with a num- 
ber of rather large spigots (tiny finger-like projections that 
house the openings of the silk glands). A short obtuse colulus is 
present immediately in front of the anterior spinnerets. The 
anal tubercle is prominent, roughly triangular in shape, and 
subsegmented. 

The long legs are of unequal length (Figs. 4, 49, 50, 121, 138). 
The relative length of the legs is useful in separating genera and 
species groups. The order of leg length may be I-II-IV-III, 
I.II=IV-III, I-II-III-IV or IV-I-II-III. The "males have more 
elongate tarsi and metatarsi than the females and longer legs 
in relation to their body length (Tables II and III). The legs 
are armed with very long spines, one of the most conspicuous 
characteristics of the family (Figs. 4, 49, 50, 121, 138). The 
trochanters have a shallow, crescent-shaped depression on the 
ventral surface. 

There are three tarsal claws, the superior pair largest and 
provided with many fine teeth, the single inferior claw very 
small, with two or three fine teeth. 

The integument of most oxyopids is copiously supplied with 
flattened, appressed hairs of varying colors, but usually ellipti- 
cal or spatulate in shape. There are also modified translucent, 
flattened hairs, very scale-like in appearance, that give off 
brilliant metallic hues of lavender, green and blue. The spatu- 
late hairs often cover much of the body and create the charac- 
teristic color patterns of the species (particularly in the genus 
Oxyopes). 

The structure of the genitalia has a definite pattern within 
each genus. The palpi and epigyna are of prime importance in 
determining generic as well as specific affinities. The different 
structural patterns are discussed under each genus. 

KEY TO GENERA 

la. Posterior cheliceral margin without teeth; ALE row obviously wider 
than PME row; posterior eye row (PME and PLE) only slightly pro- 
curved (Pigs. 137, 142). Living specimens of bright green color 

Peucetia 

lb. Posterior cheliceral margin with a single tooth on each side; ALE row 
subequal to PME row (Figs. 2, 3) or PME much wider than ALE 
(Figs. 109, 111) ; posterior eye row (PME and PLE) strongly pro- 
curved (Figs. 2, 3, or Figs. 109, 111). Living specimens not green 
in color 2 



BRADY: LYNX SPIDERS OF NORTH AMERICA 447 

2a. Distance between PME suheciual to distaiicc lictwccii I'.MK and I'LE 

on each side (Figs. 2, 3) .3 

2b. Distance between PME much greater than distance from PME to PLE 

on each side (Figs. 109, 111) Ilaviataliwa (except S. Jielia) 

3a. Leg IV robust, obviously longer than leg Til. Order of leg length I-II- 

IV-III, I-II = IV-III or IV-I-II-III O.ri/opcs 

3b. Leg IV small, subcqual in size to leg III. Order of log length I-II- 

III-IV Hamatalhva helia 

OXYOPES Latreille 

Ozyopes Latreille, 1804, Tableau methodique des Insectes, Nouveau Diet. 
Hist. Nat., Arachnides, 24:135. Type species by monotypy: O. 
hclcropliihnlmiis Latreille, 1804, op. cit., 24:13.5. 

Characffrisfics. Eyes: AME smallest; PME .iiid PLE siil)- 
equal in size, larger than AME. but sli<ihtly sniallcr than ALE. 
ALE largest. 

Width of eye roAvs: AME row much the smaUest ; ALE row 
subequal to the PME row. PLE row much the widest (Table 11). 

Cephalothorax high and convex, the cephalic region some- 
times slightly elevated, sloping sharply at the thoracic declivily 
and along the sides. The face is almost vertical. 

Labium longer than wide (Fig. 10). Endites exceeding the 
length of labium and converging in front of it. 

Abdomen elongate, widest immediately behind base and t;ii)er- 
ing to spinnerets. 

Legs very long in comparison to body length and nne(|ual in 
relative length (Table II). Legs with numerous stout spines. 
Order of leg length I-II-IV-III or I-II=IV-III {aclcistus group, 
0. salticus, 0. scalaris) and IV-I-II-III (apollo group). Patel- 
lae-tibiae longer than femora or metatarsi, except on leg IV 
in some cases, thereby serving as a good indicator of leg lengtli. 

Integument richly supplied with flattened spatulate-shaped 
hairs that provide contrasting color patterns over most of body. 

In the ventral view of the left palpus of the male the emhohis 
curves from the l:)ase along the mesal edge of the cymbium, and 
describes a clockwise arc. The distal end of the embolus rests on 
a well-developed conductor (at approximately one o'clock), 
characteristic in size and shape for each species. At the point 
where the embolus arises, there is usually a structure which 1 
call the lamellar apophysis, also of characteristic form and size 
for each species (Fig. 36). 

Females with the epigyna variable, but with the internal 
genitalia of rather simple structure and generally uniform 



448 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

throughout the genus. External openings of the epigynum 
leading to a pair of heavily sclerotized bulb-shaped seminal re- 
ceptacles. From the dorsal side of the seminal receptacles, a 
pair of lightly sclerotized, almost invisible, fertilization ducts 
arise and continue ventrally around the posterior neck of these 
bulbs (Fig. 15). 

Species Groups of Oxyopes 

The genus Oxyopes in North America may be separated into 
several distinct species groups : the acleistus group containing 
four species, the apollo group containing six species, and two 
independent specie-s, 0. salticus and 0. scalaris. The establish- 
ment of these groups is based on similarities in genitalia, body 
structure, color pattern, and the relative length of legs. 

Acleistus group. In the acleistus group (0. acleistus, 0. aitr- 
ciis, 0. arjlossns, 0. occiclens), the females have a broad, heavily 
sclerotized bar forming the epigynum and covering the open- 
ings of the .seminal receptacles (Figs. 16, 20, 22, 24) or a less 
heavily sclerotized epigynum with an inverse T-shaped central 
opening as in Figures 14 and 19. The palpi of the males have 
well-developed retrolateral tibial apophyses (Figs. 34, 36, 38. 
40). Oxyopes acleistus, 0. aureus and 0. aglossus have distinct 
black lines on the ventral surfaces of femora I, II and III. 
Oxyopes occidens is the most divergent member of this group. 
It does not have these black lines under the femora, but has the 
same general color pattern. The epigynum as well as the male 
palpus and relative length of the legs of 0. occidens ally it 
to the acleistus group. 

The lynx spiders of the acleistus group all have the first leg 
longest and well developed. The second leg is usually next 
in length, although the fourth leg may be almost as long and 
is always more robust than the second leg. The patellae-tibiae 
are always I-II-IV-III in order of length (Table II). Femora 
IV are always strongly developed and the metatarsi exceed the 
length of the patellae-tibiae on leg IV. 

A comparison of the species in this group is provided in Dia- 
gram 3 and a comparison of the acleistus group to other species 
of Oxyopes is provided by Table II. Oxyopes acleistus and 0. 
aureus are the two species most alike in the group. They are 
very similar in the form of genitalia and in coloration and are 
entirely allopatric in distribution. Oxyopes acleistus, how- 
ever, appears to be consistently smaller than 0. aureus. Other 



BRADY : LYNX SPIDERS OF NORTH AMERICA 449 

diii:crence.s between tliesc two species are noted under the diag- 
nosis of 0. acleistus. Oxyopes aglossus is partially sympatrie 
with 0. aureus (Map 1) and is definitely smaller in size (Table 
II). Oxyopes aglossus and 0. acleistus are closer in size than 
0. aureus and 0. acleistus and may exclude one another from 
their ranges (Map 1). Observing the distribution of these spe- 
cies, we may theorize that 0. aglossus has provided a barrier to 
gene flow between 0. aureus and 0. acleistus and effectively 
isolated these two speices. 

The following hypothesis of historical events might explain 
the present distributions of these three species. Oxyopes aureus 
and 0. acleistus were once a continuous interbreeding popula- 
tion, distributed from Mexico along the Gulf Coast into Florida, 
and this hypothetic species reached as far north as Kansas, Mis- 
souri, Illinois and Indiana. This was during an interglacial 
period of a more warm and favorable climate. Oxyopes aglossus 
at this time was even more northerly in distribution, reaching 
southern Canada. It was excluded from the range of 0. aureus- 
ocleistus, the postulated species, because of its similar ecological 
requirements. Later in their history these three incipient species 
were forced to retreat southward. For our purposes we may 
think of their retreat as coinciding with the advance of the ice 
cap during the Pleistocene. Oxyopes acleistus retreated into 
penin.sular Florida while 0. aureus retreated to the southern tij) 
of Texas and northern Mexico. The advancing glacier also 
forced 0. aglossus southward and it occupied the regions along 
the Gulf Coast vacated by 0. aureus and 0. acleistus, forming an 
effective barrier to gene flow between these two species. In this 
case we have probable historical events explaining the present 
distribution of these three species. 

The relationships of the four species of the acleistus group 
are summarized in the following diagram. This diagram is 
based primarily upon morphological characters, but also takes 
into account distribution. 

The lines leading to 0. aglossus and 0. occidcns could be 
drawn to the right of 0. acleistus and 0. aureus as well as to the 
left, indicating equal similarity to both of these species. Oxyopes 
occidens is somewhat closer to 0. aglossus in genitalia, but re- 
sembles 0. aureus more in size and coloration. 

Apollo group. The apollo group constitutes another complex 
of species recognized by their color pattern, all having the fourth 
leg longest and the palpus of the males with a well-developed 
apophysis on the patella, with the one exception of 0. felinus. 



450 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

aclelstus aureus aglossus occidens 



Diagram 1 

In addition, the epigyna of the females that are known have a 
heavily selerotized posterior rim in the shape of a crescent or 
bow as in Figures 47, 51, 53, 54. This species group consists 
of 0. apollo and 0. floridanus, two closely related species in 
the East, and 0. tridens, 0. pardus, 0. lynx, and 0. felinus, all 
found in the southwestern United States. 

A comparison of the species in this group is provided in 
Diagram 4 and a comparison of the apollo group to other species 
of Oxyopcs is supplied by Table II. Only three species were 
abundant enough in collections to construct Dice-Leraas graphs 
in Diagram 4. These graphs indicate that 0. apollo and 0. 
floridanus are morphologically very similar. These two species 
are separated primarily by differences in the male palpi and 
a greater abundance of spatulate hairs in 0. floridanus. These 
slight differences are, however, indicative of reproductive iso- 
lation. The fact that 0. floridanus is restricted to peninsular 
Florida serves to support its recognition as a separate species. 
Collections from intermediate geographic regions (Louisiana, 
Mississippi, Alabama, and western Florida) will help to de- 
termine if these two species, as I have called them, are repro- 
ductively isolated. 

The western species of the apollo group, which we can define 
collectively as the tridens complex, are apparently all sympatrie 
in a broad sense. They may be separated from one another alti- 
tudiually or by very restricted distributions within a geographic 
area, such as in mountain ranges (geographic isolation) or in 



BRADY : LYNX SPIDERS OF NORTH AMERICA 



451 



certain liabitats (ecological isolation). Oxyopcs tridens seems 
to have a relatively wide distribution, however, being found 
at various altitudes and over a relatively wide geographic area. 
The reason for the extreme rareness of the other three species of 
the tridens complex (0. hjnx, 0. pardus, and 0. felinus) may 
be attributed to their habits. All of the species of the apollo 
group are apparently ground inhabitants, that is, they run or 
hop about over bare ground. In the Southwest, Oxyopcs tri- 
dens aud related species have been collected as they jumped 
about on dry hillsides strewn with boidders and smaller rocks, 
but with very little vegetation. These species have been rarely 
taken by sweeping vegetation, but they may occur on certain 
types of plants when these are present. 

It is significant to note that W. II. Whitcomb (pers. com.), 
who has collected extremely large numbers of Oxyopcs salticus 
and a good number of specimens of Oxyopcs aglossus by sweep- 
ing crop plants in Arkansas, has failed to collect even one speci- 
men of 0. apollo by this method. Instead, O. apollo is recovered 
rather frequently in pitfall traps laid flush with the ground. 

The relationships of the six species that constitute the apollo 
species group are summarized in Diagram 2. This diagram is 
based primarily upon morphological similarities, but takes into 
account distribution as well. The male palpus of 0. felinus 
does not have a patellar apophysis, but the color pattern, the 
structure of palpal sclerites and the long fourth leg places it 
near 0. tridens, 0. pardus and 0. lynx. Oxyopcs apollo and 
0. floridanns are obviously very similar to each other. Oxyopcs 



apol lo 



floridanus 



tridens pardus lynx 



felinus 




Diagram 



452 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

tridens, 0. lynx and 0. pardns could be placed in any sequence, 
being equally alike or distinct. When the females of the latter 
two species and 0. felinus are known, their relationships will be- 
come more clear. 

The remaining two species of Oxyopes, 0. scalaris and 0. salfi- 
cus, are very different from the other species north of Mexico 
and in their proper context would constitute separate species 
groups. Oxyopes scalaris, as has been pointed out, is similar to 
0. ramosus and 0. heterophthalmus of Europe. Since 0. scalaris 
is found as far north as Labrador we might hypothesize that 
the progenitors of this species came from the Eurasian continent 
by way of the British Isles, Iceland, and CTreenland, to Canada 
where they occur today. Again, this migration must have oc- 
curred when the climate in these areas was warmer and more 
favorable. There are no oxyopids known from Iceland or Green- 
land at the present time. 

Oxyopes salticus bears some resemblance to the four species 
in the acleistus group and might be placed with them in a sub- 
generic grouping. Comparison of 0. salticus and 0. scalaris with 
other species of Oxyopes can be seen in Diagrams 5 and 6. In 
Diagram 6, 0. apollo and 0. tridens have patella-tibia IV much 
longer than I. This trend in the apollo group, for the fourth 
patella-tibia to be longest, is evident in the figures in Table II 
and is correlated with the great length of the fourth pair of legs. 

KEY TO SPECIES OF OXYOPES 
MALES 

la. With distinct black lines on tlie ventral surfaces of femora I and II 2 

lb. Without distinct black lines on the ventral surfaces of femora I and II 
5 

2a. With a well-developed retrolateral tibial apophysis (Figs. 35-40) and 
no tuft or brush of stiff hairs on the ventral surface of the patella of 
the palpus. Color pattern as in Figures 27-32 3 

2b. With the tibial apophysis concave, no well-developed retrolateral tibial 
apophysis, and with a tuft or brush of stiff hairs on the ventral surface 
of the patella of the palpus. Color pattern as in Figures 80-84. Palpus 
as in Figures 104, 105 salticus 

3a. With two teeth at the base of the retrolateral til)ial apophysis of tiic 
palpus (Figs. 35, 37) 4 

3b. With only a single tooth at the base of the retrolateral tiliinl apoiiliysis 
of the palpus (Fig. 39) (u/lussits 



BRADY : LYNX SPIDERS OF NORTH AMERICA 453 

4a. Palpus with a lar-^e lamellar apophysis and tibial apophysis forniiiiK 
a less acute angle at the distal end (Figs. 35, 3(5). Texas and Louisiana 

aureus 

4b. Palpus with a small lamellar apophysis and tibial apophysis forming a 

more acute angle at the distal end (Figs. 37, 38). Florida. . . acleistus 

5a. A conspicuous apophysis on the patella of the palpus and/or dorsal 

color pattern of longitudinal black and white stripes running the length 

of the body (Figs. 56-63). Leg IV longer than leg I 6 

5b. Patella of palpus without apophysis and dorsal color pattern not black 

and white stripes running length of body. Leg I longer than leg IV. 9 

6a. Color pattern of longitudinal black and white stripes running length of 

body (Figs. 56-63) 7 

6b. Color pattern not black and white stripes running length of body. 

Pattern as illustrated in Figures 72, 73 or 76, 77 8 

7a. Palpus illustrated in Figures 70 and 71 tridens 

7b. Palpus illustrated in Figures 68 and 69 pardits 

7c. Palpus illustrated in Figures 66 and 67 lynx 

7d. Palpus illustrated in Figures 64 and 65 felinus 

8a. Palpus illustrated in Figures 74 and 75 apollo 

8b. Palpus illustrated in Figures 78 and 79 floridanus 

9a. Light yellow or golden in general appearance. Pattern illustrated in 

Figures 25 and 26. Palpus in Figures 33 and 34 occidens 

9b. Eusset brown, dark brown or gray in general appearance. Pattern il- 
lustrated in Figures 87 and 88. Palpus in Figures 106-107 . . . scalaris 

KEY TO SPECIES OF OXYOPES 
FEMALES 

la. With distinct black lines on the ventral surfaces of femora I and II 2 

11). Without distinct black lines on the ventral surfaces of femora I and II 5 

2a. Epigynum with an anteriorly directed scape (Figs. 91-96). Pattern 
illustrated in Figures 85 and 86 salticus 

2b. Epigynum without an anteriorly directed scape; with a more or less 
well-developed posterior sclerotized rim or a heavily sclerotized trans- 
verse bar 3 

3a. Epigynum consisting of a broad transverse bar (Fig. 22) ; pattern 
illustrated in Figures 9, 11, 12 aglossus 

3b. Epigynum consisting of a sclerotized transverse posterior rim that has 
an anterior depression or with a less-heavily sclerotized transverse piece 
disclosing a central cavity (Figs. 14 and 16, 19 and 20) 4 

4a. Central cavity of epigynum large, almost elliptical in shape (Fig. 19) 
or enclosed by a transverse sclerotized bar in which case the epigynum 
appears as in Figure 17 or 20. Florida aelcisiufi 

4b. Central cavity of epigynum narrow, inversely T-shaped (Fig. 14) or 
enclosed by a transverse sclerotized bar in which case the epigynum 
appears as in Figure 16 or 17. Louisiana and Texas aureus 



454 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

5a. Leg IV longer than leg I 6 

5b. Leg I longer than leg IV 8 

6a. Color pattern of longitudinal black and white stripes extending length 
of body (Fig. 46) ; epigynum with strongly raised crescent-shaped 
posterior rim (Figs. 53 and 54) tridens 

6b. Color pattern not of longitudinal black and white stripes, but as in 
Figure 42 or 44; epigynum with posterior rim only slightly raised 
(Figs. 47 and 51) 7 

7a. Carapace, abdomen and legs heavily clothed with spatulate or elliptical- 
shaped, flattened white hairs. Florida floridanus 

7b. Carapace mostly glabrous with scattered white hairs along vertical 
sides. Tennessee, Missouri, Arkansas, Louisiana, and westward . . apollo 

8a. Eusset brown, dark brown or gray in general appearance with con- 
trasting white markings (Fig. 90) ; epigynum with an anteriorly di- 
rected scape (Figs. 98 and 99) scalaris 

8b. Light yellow or golden in general appearance (Fig. 8) ; epigynum a 
transverse bar (Fig. 24) occidens 

Species Descriptions 

OxYOPES acleistus Chamberliii 

Figures 5, 6, 18-20, 29, 30, 37, 38. Map 1. 

Oxyopes acleistus Chamberlin, 1929, Ent. News, 40:19, fig. 3, $. Female 
holotype from Sanford, Seminole Co., Florida, in the American Mu- 
seum of Natural History, examined. Eoewcr, 1954, Katalog der Araneae 
2(a) :330. Bonnet, 1958, Bibliographia Araneorum, 2(4):3223. 
Oxyopes nelsoni Bryant, 1945, Psyche, 52(3-4) :180, figs. 5, 7, $, ?. Fe- 
male holotype from Sebastian, Indian Eiver Co., Florida, in tlie Museum 
of Comparative Zoology, examined. NEW SYNONYMY. 
Discussion. The female described by Miss Bryant as Oxyopes 
nelsoni has a greater sclerotization of the epigynum, reducing 
the size of the central cavity that leads to the openings of the 
seminal receptacles (Fig. 20). The original description by R. 
V. Chamberlin was based on a specimen similar to Figure 19 
in which the epigynum is less heavily sclerotized, and there is 
a characteristically shaped central cavity leading to the open- 
ings of the seminal receptacles. These two distinct forms of the 
epigynum are apparently characteristic of 0. acleistus. Of the 
seven females of 0. acleistus examined, two have the enclosed 
or "7ielsoni" form of epigynum, three have the open or ^'acleis- 
tus" form of epigynum, and one is a bilateral combination sim- 
ilar to Figure 17. This dimorphism of the epigynum is found 
in the closely related species O. aureus in which both types occur 
in the same population as well as individuals that have one-half 



]}RADY : LYXX SPIDKHS OF NORTH AMERICA 455 

of the ppigyiiura enclosod and oiic-IiaU' open. The male allotype 
of 0. nclsoni from Sebastian, Florida, is identical with males 
of 0. acleisfus. 

Structure. Lenp'th of seven females, 4.4-6.5 mm, mean 5.3 
mm; lenp'th of nine males, 3.8-4.8 mm, mean 4.4 mm. Order of 
leg len<>tli I-II-IV-ITI. For comparison of certain diagnostic 
measurements of 0. aclcistus with those of other species see 
Table II and Diagram 3. 

Color. Female. Pattern illu.strated in Figures 5 and 6. Eyes 
circled with black, eye region dark brown, but heavily clothed 
with white hair. Face pale yellow to ivory. Vertical brown 
stripes beginning broadly under ALE, narrowing considerably 
at lower edge of clypeus and continuing to distal region of chel- 
icerae. Carapace pale yellow to ivory with darker brown mark- 
ings at anterior end. Wide dark brown submarginal stripes 
originating under PLE and continuing to posterior declivity. 
Thoracic groove a thin brown line. Darker patterns and stripes 
on carapace formed by tiny spatulate hairs. 

Dorsum of abdomen pale yellow or cream colored from base 
to tip of spinnerets, bordered by dark brown or black. Two 
pairs of white indentations directed diagonally forward. Car- 
diac area slightly darker. Venter of abdomen pale yellow or 
cream with faintly indicated broad median stripe of darker 
brown, this stripe bordered by thin whitish lines. One specimen 
has the median stripe quite dark and distinct. 

Legs pale yellow to ivory with longitudinal median black 
stripe on ventral surface of femora I, II and III. The black 
stripe is obsolete on leg IV, but may be represented by a series 
of dashes. The leg segments distal to the femora tend to be 
slightly darker and in some cases gray hairs form irregular 
dusky markings, particularly on the distal half of the femora. 
There may also be a slight green metallic sheen from the legs, 
although not so distinct as in the male. 

Endites cream or ivory colored with black seopulae at inner 
margins of distal region. Labium slightly darker. Sternum 
ivory. 

In some cases the spatulate hairs of the carapace may be 
rubbed oif and the darker submarginal stripes are only faintly 
represented. Several of the specimens appear much lighter than 
in Figure 6 because the pale central area covers more of the 
dorsum of the abdomen and the marginal areas are not so dark 
and contrasting. Thej' appear much the same as 0. aureus in 
Figure 3. 



456 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Male. Pattern illustrated in Figures 29 and 30. Eyes circled 
in black with black bands extending from each eye toward 
center of eye hexagon. Face light brownish yellow or gold with 
vertical black lines extending from ALE to distal region of 
chelicerae, as in Figure 29, or with face mostly black, as in 
Figure 27. Eye region with iridescent scales particularly from 
ALE to PME. The palpi are velvety black, and in some speci- 
mens they exhibit a blue iridescence. 

Carapace brownish yellow or golden with broad submarginal 
brown stripes as in female. 

Dorsum of abdomen ranges from almost white to gray de- 
pending upon abundance of spatulate hairs. Sides of dorsum 
are gray to black. Dorsum with scattered iridescent scales. 
Venter of abdomen ranging from pale yellow with dusky 
median stripe to gray with a black median stripe outlined in 
yellow. Iridescent scales more numerous on venter than dorsum. 

Legs yellow with black stripes on the ventral surfaces of 
femora I, II, and III. In most specimens the legs exhibit a 
green metallic sheen due to iridescent scales. 

Endites pale yellow to brown with the distal ends lighter. 
Labium darker, brownish yellow to dark brown. Scopulae 
black. Sternum pale yellow or cream. 

Diagnosis. 0.ryopes aclcistus is most similar to 0. aureus in 
coloration and in the form of the male and female genitalia. A 
comparison of Figure 14 with Figure 19, however, reveals dis- 
tinct differences between the central cavities of the epigyna. 
In the palpi the median apophysis of 0. acleistus is smaller than 
in 0. aureus (compare Fig. 38 with Fig. 36) and the tibial 
apophysis of 0. acleistus forms a more acute angle toward its 
distal end than in 0. aureus (compare Fig. 37 with Fig. 35). 

Because 0. acleistus and 0. aureus are similar and occur as 
distinct allopatric populations, one might assume them to be 
subspecies (Map 1). However, in addition to the differences in 
genitalia already noted, a comparison of the diagnostic meas- 
urements in Table II and in Diagram 1 reveals that 0. aureus 
is probably consistently larger than 0. acleistus. All of these 
differences indicate that isolating mechanisms exist between 
the two, and that 0. acleistus and 0. aureus would not in- 
terbreed if they w^ere to come into contact. 

It is interesting that in many cases (Wallace, 1942a. 1942b; 
Brady, 1962; McCrone, 1963) the distribution of spider sjM^cies 



BRADY : LYNX SPIDERS OF NORTH AMERICA 457 

found in Florida is restrictod to the peninsula or does not ex- 
tend far beyond the limits of the state. Almost any larj^fe re- 
vision will reveal cases of this limited distribution. 

Natural history. Males and females of this species were col- 
lected by swee])in<i- .short grass and herbaceous veo-etation. 
During early June they did not occur in great abundance and 
only a few specimens were captured in approximately two 
hours of sweeping. Oxyopes acleistus seems to prefer low vege- 
tation in shaded areas. A single male was found running over 
the outside wall of a tent at Gold Head Branch State Park and 
a female was taken from the top of a picnic table at the same 
location. 

Distrihution. Florida (Map 1). 

Records. Florida. Dade Co.: $ (THH) ; Homestead 9 9. 
Highlands Co. : Highlands Hammock St. Pk. near Sebring, 21 
June 1962, S $ 9 9 (ARE, JAB). Indian River Co.: Se- 
bastian, 1-8 Apr. 1944, $ $ 9 (GN). Orange Co.: 10 mi. SW 
of Orlando, 23 Aug. 1944, $ (MN). Putnam Co.: Gold Head 
Branch St. Pk., 13 June 1962, 9 (ARB), 14 June 1962, $ 
(C. Zeiger) ; Welaka, 21 June 1946, S $ (R. E. Bellamy). 
Seminole Co.: Sanford, 27 July 1927, 9 (Stone). 

Oxyopes aureus sp. n. 
Figures 1-4, 13-17, 27, 28, 35, 36. Map 1. 

Holotype. Female from Bentsen State Park, 6 mi. SW of 
Mission, Hidalgo Co., Texas, 30 June 1962 (A. R. Brady) in the 
Museum of Comparative Zoology. The specific name is an adjec- 
tive meaning golden. 

Discussion. Oxyopes aureus is probably the most variable 
species of this genus in North America with regard to local 
populations. The female may appear dark with a distinct ab- 
dominal pattern (Fig. 1), or may appear much lighter (Fig. 
3). In addition, the male may have the face lined with black 
(Fig. 29) or almost entirely black (Fig. 27). The female 
epigynum also shows considerable variation (Figs. 14-17). 
Of 30 females examined, 17 have the epigynum as in Figure 14, 
eight as in Figure 16, and five females have a bilaterally di\'ided 
combination as in Figure 17. All three types of epigyna are 
encountered in the same local population. 

Since there are two rather distinct epigyna (Figs. 14, 16) 
and two relatively distinct color patterns (Figs. 1, 3), it was 



458 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

thought that two species might be present. The correlation be- 
tween color pattern and the type of epigynum was closely 
checked. Although many specimens with a color pattern as in 
Figure 1 had an epigynum as in Figure 16, and many speci- 
mens with a color pattern as in Figure 3 had an epigynum 
as in Figure 14, these combinations were not found in a num- 
ber of individuals. Also the color patterns formed a continuum 
and in some cases were difficult to classify. 

The size of the female specimens was also checked carefully 
with respect to the possession of a particular color pattern 
and/or a specific type of epigynum. Again there was no definite 
relationship. It appears that the variation in this species rep- 
resents a case of genetic polymorphism and is not related to age 
or size, or caused by gravidity of the female. 

That only one species is represented here seems certain if it 
is considered that: (1) all types of variants occur in local 
populations with no visible ecological differences, (2) internally 
the female genitalia are alike, (3) intermediates (Fig. 17) 
occur between epigynal types, and (4) there is only one male 
encountered, i.e. the male palpus shows no variation. The same 
kind of polymorphism that occurs in 0. aureus is present in 
0. acleistus as well. Both species are extremely interesting 
because of this phenomenon and deserve further analysis, 
mainly because much of spider taxonomy in particular, and 
arthropod taxonomy in general, is based on the "invariability" 
of genitalic structure. 

Structure. Length of 30 females, 5.0-7.3 mm, mean 6.0 mm; 
length of 26 males. 4.1-5.2 mm, mean 4.6 mm. Order of leg 
length I-II-IV-III. For compari.son of certain diagnostic meas- 
urements of 0. aureus with those of other species see Table II 
and Diagram 3. 

Color. Female. Pattern variable, ranging from dark colored, 
well-marked individuals as in Figure 1 to lighter, less dis- 
tinctly marked specimens as in Figure 3. Eye region dark brown, 
thickly clothed with white appressed hairs. Eyes circled in black 
with a black band running from each toward center of eye 
hexagon. Face pale yellow to cream or ivory. Vertical brown 
stripes beginning broadly under ALE, narrowing considerably 
at lower edge of clypeus and continuing to subdistal region of 
chelicerae. 

Carapace cream colored to ivory. Wide submarginal stripes 
of brown spatulate hairs beginning below PLE and continuing 



BRADY : LYNX SPIDERS OF NORTH AMERICA 459 

posteriorly to thoracic declivity. AVell-markcd s])cciiiiens have 
in addition dark markinofs behind the PME and surroundinjif 
the thoracic groove, produced by appressed spatulate hairs. 

Doraum of abdomen white to cream colored. In well-marked 
individuals, white overlaid Avith brownish yellow si)atulate 
hairs produces a golden appearance. Cardiac region with lance- 
olate marking of slightly darker color, outlined in brown. Lance- 
olate mark absent in many pale specimens. Pale central region 
of dorsum more or less exteiLsive (compare Fig. 1 with Fig. 3) 
and bordered b}^ dark brown or black. Two pairs of pale lateral 
indentations on posterior half of abdomen, accented with white 
hairs and directed anteriorly. Venter of abdomen cream colored 
with median longitudinal brown stripe from epigastric furrow 
to spinnerets. 

Legs ivory. Distinct black median longitudinal stripes on 
ventral surfaces of femora I, II, and usually III. Stripes less 
distinct on femur IV, sometimes absent. Dusky markings on 
legs, more pronounced on distal ends of femora, tibiae and 
distal segments. Legs duskier on well-marked specimens. 

Endites ivory with dark sclerotized outside borders, black 
scopulae. Labium cream colored, sometimes with dusky cloth- 
ing of fine hair making it darker. Sternum ivory, dusky around 
margin, with conspicuous black hairs. 

Specimens marked as in Figure 1 are characterized by a much 
greater abundance of scale-like spatulate hairs (both light and 
dark) that form the type of pattern illustrated. When these 
are rubbed away the specimens tend to become lighter in appear- 
ance and more like Figure 3. 

Male. Pattern illustrated in Figures 27 and 28. Eye region 
dark brown to black. No w^hite hairs present. Iridescent 
spatulate hairs from ALE to AME. Palpi velvety black with 
metallic blue sheen. Face dark orange-brown with dusky mark- 
ings as in Figure 29, to almost entirely black. Some specimens 
have a definite black reticulum and most of the face and cheli- 
eerae black (Fig. 27). Vertical black stripes are often indis- 
tinguishable, being completely obliterated by black color on the 
chelicerae as well as on the clypeus. 

Carapace light yellow-orange or golden. Dusky submarginal 
stripes beginning under PLE, curving dorsally and continuing 
to posterior declivity of thoracic region or submarginal stripes 
absent wdth the carapace almost glabrous, having only a few 
scattered spatulate hairs. 



460 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Dorsum of abdomen with broad median area of ivory to 
cream, covered with grayish scales in greater or less abundance. 
Bordered on .sides by dark gray-brown. Venter cream to pale 
yellow with broad median longitudinal gray-brown stripe from 
epigastric furrow to base of spinnerets or venter almost en- 
tirely black with median stripe bordered by a thin pale line. 
Black patch over genital area, lung book covers pale yellow 
or cream. Iridescent scales usually numerous on venter. 

Legs ivory with distinct black stripes on ventral surface of 
femora I and II, but these stripes only faintly represented on 
femora III and IV. Scattered dusky markings, usually on 
dorsal surface of leg segments. Femora with faint green metal- 
lic luster. 

Endites pale yellow to ivory with outer edges dark brown, 
sclerotized. Usually lighter in color at distal ends, with black 
scopulae. Labium darker, brownish. Sternum ivory to cream. 

Diagnosis. Oxyopes aureus is most similar to 0. aclcistus, 
which it resembles in coloration and in genitalic structure. 
These two species can be best differentiated by comparing the 
epigynum of 0. aureus (Fig. 14) with 0. acleistus (Fig. 19). 
For other differences see the discussion under the diagnosis of 
0. acleistus. 

Natural history. In southern Texas adult males of 0. aureus 
first appear in April and have been collected through Septem- 
ber. Females appear in May and may be found as late as No- 
vember. Adult individuals are most abundant in late June 
and early July. Oxyopes aureus was collected by sweeping 
grass and other herbaceous vegetation at Corpus Christi State 
Park and Bentsen State Park in southern Texas. These spiders 
were most abundant in relatively short vegetation (6-8 inches) 
in shaded areas, particularly under the cover of trees. At 
Corpus Christi Park they occurred in close proximity to 0. 
salticus. The latter species, however, was much more abundant 
in open unshaded areas and in taller grass along the lake shore. 
Nearly all of the specimens of 0. salticus that were collected 
from 28 June-1 July at the above localities were immature. Ma- 
ture males and females of 0. aureus were relatively abundant 
during this same period. At Goose Island State Park 0. aureus 
was collected in sweeping Compositae. This species has been 
found in mud-daubers' nests, but it is not taken in great num- 
bers by these wasps. 

Disti-ihution. Louisiana, Texas, and Mexico (Map 1). 

Records. Louisiana. East Baton Rouge Par. : Baton Rouge, 



BRADV : LVNX SI'IDKIJS OF NORTH A.MKKiCA 



4()1 



June 1954, 9 (NB). Texas. Aransas; Ataeosa; Bee; Brazoria ; 
Brewster; Calhoun; Cameron; Dallas; Harris; HidaljiO; San 
Patricio ; Starr ; Travis. 

MEXICO. Tamaiilipas. Rio (jnalolcjo near Forloii, 16 Apr. 
1938, S 9 9 (LID, B. Brown). San Luis Postosi. Iluichilui- 
aj-an, 19 May 1952, $ (MA(\ WJG, RS), 10 mi. N of A\allcs, 
23 July 1945, S (A. M. Dame). 




Map 1 

OxYOPES AGLOssus Chamberlin 

Figures 9-12, 21, 22, 31, 32, 39, 40. :\lap 1. 

Oxyopes aglossus Chamberlin, 1929, Ent. News, 40:17, figs. 1, 2, $, $. Fe- 
male holotype from Billy's Island, Okefenokee Swamp, Georgia, in the 
American Museum of Natural History, examined. Eoewer, 1954, Kata- 
log der Araneae, 2(a) :333. Bonnet, 1958, Bibliographia Araneorum, 
2(4):3223. 
Discussion. O.ryopes aglossus does not exhibit the polymor- 
phism shown in 0. aclcistus and 0. aureus. There is also little 
geographic variation in color over its entire range of distribution 
(see Map 1). The affinities of 0. aglossus undoubtedly reside 
with 0. acleistus and 0. aureus, and it is considered to belong to 
the same species group. 

Structure. Length of 30 females, 4.5 - 6.7 mm, mean 5.4 mm ; 
length of 26 males, 3.9 - 4.8 mm, mean 4.4 mm. For comparison 
of certain diagnostic measurements of 0. aglossus with those of 
other species see Table II and Diagram 3. 



462 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Color. Female. Pattern illustrated in Figures 9, 11 and 12. 
Eyes circled in black with black band leading from each eye 
toward center of eye hexagon. Eye region thickly clothed with 
white hair. Face cream to pale yellow. Black stripes beginning 
below AME and continuing to distal region of ehelicerae. 

Carapace cream to pale yellow. Wide brown submarginal 
stripes originating anteriorly below ALE and continuing to 
thoracic declivity. Often an irregular brown pattern behind 
PME and surrounding thoracic groove. 

Dorsum of abdomen cream to pale yellow ; often with white 
pigment underlying integument, pigment most conspicuous near 
anterior end of abdomen. Cardiac area pale, faintly outlined 
by darker brown spatulate hairs. Lateral areas brown or ir- 
regularly spotted with brown. Usually two pairs of indentations 
from pale central region into darker lateral areas are visible on 
posterior half. Venter of abdomen cream colored with broad 
median dark brown or black stripe from epigastric furrow to 
spinnerets. 

Legs pale yellow. Ventral surfaces of femora I and II with 
black median longitudinal stripes ; represented on femora III 
and IV only by a series of black dashes. 

Endites pale yellow ; sclerotized region around outer edges, 
brown. Labium pale yellow. Sternum cream to pale yellow. 

Male. Pattern as illustrated in Figures 31 and 32. Eyes 
circled with black and with black bands extending toward center 
of eye hexagon. Iridescent scales from ALE to PME. Palpi 
black with iridescent blue sheen. Vertical black stripes from 
AME to distal region of ehelicerae. Distal ends of ehelicerae 
pale. 

Carapace pale yellow-orange (golden) to brownish yellow. 
Broad dusky submarginal stripes. Vertical sides lighter in color 
than dorsal surface. 

Dorsum of abdomen cream with lateral areas dark brown or 
almost black due to presence of dusky scales. Pink and lavender 
iridescence occurs wherever these gray scales are present, many 
times over entire dorsal surface. Venter with very wide dark 
brown to black stripe from epigastric furrow to spinnerets, 
bordered by pale lines. In some cases the entire ventral surface 
is dark gray-brown to black and heavily covered with scales. 
Genital region dusky with lung book covers pale. 

Legs cream to yellow. Femora I and II with median ventral 
black stripe, stripes broken and indistinct on femora Til and IV. 

Endites cream to yellow with dusky markings along outer 



BRADY : LYNX SPIDERS OF NORTH AMERICA 468 

edges. Labium cream to brownish yellow. Stcniuiu ])uk' cream 
to yellow. 

Diagnosis. Oxyopcs aglossus is most similar to 0. aclcistKS 
and 0. aureus. The chief similarities are in general color pattern, 
relative length of the legs, and particularly the male palpi (Figs. 
35-40). Females of 0. aglossus are easily separated from 0. 
acleistus and 0. aureus by the form of the epigynum (compare 
Fig. 22 with Fig.s. 14, 16 and 19, 20). The differences in the 
male palpus are in the conductor, Avhich is more square at 
the distal end in 0. aglossus (compare Fig. 40 with Figs. 30 
and 38), and in the tibial apophysis, which has only a single 
tooth at the base in 0. aglossus as opposed to two teeth in 0. 
acleistus and 0. aureus (compare Fig. 39 with Figs. 35 and 37). 

Natural history. I have not collected this species in the field. 
In habits it is probably similar to 0. aureus and 0. acleistus. 
Many specimens of 0. aglossus were included in vials with 0. 
salticus so that they nuist have similar habitat preferences, that 
is, grass and other herbaceous vegetation. A number of speci- 
mens are from relatively high elevations in Tennessee and North 
Carolina, but there are also specimens from localities near sea 
level in Mississippi. Several specimens were recovered from the 
nest of Sceliphron. 

Distribution. Virginia, Tennessee, North Carolina, south to 
Alabama, Mississippi, Louisiana, and west to Texas. 

Records. Virginia. Fairfax Co. : Great Falls, 21 June, 9 
(NB). Tennessee. Grundy Co. : Beersheeba, June 1888, S- Knox 
Co.: Univ. of Tennessee Farm, 3 June 1951 S, 6 June 1951, 
9 (H. B. Reed); Knoxville, 14 July, $ (W. B. Cartwright). 
Loudon Co. : Lenoir City, 20 July 1903, S (JIIE). R()])ertson 
Co. : Green])rier, 16 June 1939, S (DCL) ; 30 mi. N of Nashville. 
16 July 1933, 9 (WJG). North Carolina. Avery Co.: Pineola, 
14 July 1903, S (JHE). Durham Co.: Duke Forest, Durham, 
13-18 June 1933, 3 6 S -A^ 9 9 :o (AMC) ; 11-20 June 1953, 6 o 
(HWL) ; 14 Sept.-ll Oct. 1935, 9 (AMC). Orange Co.: Chapel 
Hill, July, S (JHE). Transylvania Co. : Brevard, 3 July 1942. 
S$ $ :9 (Westfall). Wake Co.: Raleigh, May 1945, 9, July 
1912, 9 , 12 Aug. 1943, 6 (CSB). South Carolina. Charleston 
Co.: McClellanville, July-Aug. 1945, 9 (PV). Kershaw Co.: 
4 mi. N of Cassatt, 12 June 1935, $ (WJG). Georgia. Oke- 
fenokee Swamp, Billy's Island, June 1912, 5 9 9, Honey Island 
S $ , Mixson's Hammock, 16 June 1912, <? :4 9 9 (CRC). Ware 
Co. : Waycross, 9 . Alabama. Baldwin Co. : Silverhill, Apr.-]\Iay 
1945, $, Aug. 1947, 9 (GN). Clay Co.: Cheaha St. Pk., June 



464 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

1940, $ (AFA). Lawrence Co.: Black Warrior Nat. Forest, 
June 1939, $ $ 9 9o (AFA). Tallapoosa Co.: Alexander City, 
1-14 Aug. 1944, 3$ 9 (GN). Tuscaloosa Co.: Alberta City, 
June 1947, $ (AFA). Mississippi. George Co. : Lucedale, June 
1932, $ 9 (HD). Jackson Co.: 2-15 Sept. 1942, 9 (BM). 
Louisiana. Grant Par. : Bayou Bouef , Bringhurst, 20 June 

1941, $ (SEJ, AFA) ; State' Forest, Woodworth, 21 June 1941, 
9 9, (SEJ, AFA). Winn Par.: Kisatche Forest, Winnfield, 13 

July 1943, 9 . Arkansas. Conway Co.: 7 June 1962, $ (HEF), 
Plumerville, 12-18 June 1957, 9 (L. Moore). Texas. Jasper 
Co.: 5 mi. N of Jasper, 6 June 1936, $ 9 (SM). 

OXYOPES OCCIDENS sp. n. 

Figures 7, 8, 23-26, 33, 34. Map 1. 

Holotype. Male from Sabino Pond, Sabino Canyon, Santa 
Catalina Mtns., Pima Co., Arizona, 10 July 1962 (A. R. Brady) 
in the Museum of Comparative Zoology. The specific name is 
a noun in appo.sition meaning the West. 

Structure. Length of ten females, 5.5 - 8.4 mm, mean 6.9 mm ; 
length of five males, 5.1 - 5.6 mm, mean 5.4 mm. Order of leg 
length I-II-IV-III. For comparison of certain diagnostic meas- 
urements of 0. occidens with those of other species see Table II 
and Diagram 3. 

Color. Female. Pattern illustrated in Figures 7 and 8. Eyes 
ringed with black and with black bands directed toward center 
of hexagonal eye region. Eye region black, heavily clothed with 
white hairs. Face ivory to pale yellow. Vertical black stripes 
beginning under AME and continuing to subdistal region of 
chelicerae. Chelicerae slightly darker in color, heavily sclerotized 
outer margins dark brown. 

Carapace ivory to pale yellow. Wide brown submarginal 
stripes, originating anteriorly under PLE and continuing 
diagonally upward and posteriorly to thoracic declivity. Brown 
dashes behind PME and at thoracic groove. 

Dorsum of abdomen cream to pale yellow produced by white 
overlaid with more or less dense clothing of brown, flattened, 
elliptically-shaped hairs. Darker brown marking indicating 
cardiac region. Lateral areas dark brown with color becoming 
darker posteriorly. Dark brown or black dashes outlining the 
median pale stripe at posterior end, with a pair of pale indenta- 
tions just anterior to these. Venter of abdomen with broad 
median longitudinal stripe of light brown, outlined with white 



BRADY : LYNX SPIDERS OP NORTH AMERICA 465 

and the sides darker brown or area lateral to median dark stripe 
cream without darker markings. 

Legs ivory to pale cream without any distinct darker mark- 
ings. No black stripes on femora. 

Endites pale cream to pale yellow with black scopulae at 
distal ends. Labium darker brown with reddish tinge. Sternum 
ivory to cream. 

Male. Pattern illustrated in Figures 25 and 26. Eye region 
dark brown or black without white hairs. Iridescent scales over 
eye region producing a metallic lavender or green luster, most 
noticeable between ALE. Scales scattered over face as well. 
Palpi black, heavily clothed with long black hair. 

Carapace cream to pale yellow with very light brown sub- 
marginal stripes formed by short hairs. Thoracic groove 
faintly indicated. 

Dorsum of abdomen with median white area from base to 
spinnerets, giving off a pair of lateral white dashes posteriorly. 
Covered by very light brown spatulate hairs and scattered iri- 
descent scales. Lanceolate mark of light brown in cardiac area. 
Venter with wide, brown, median longitudinal stripe, bordered 
by thin white lines on each side. Lateral area very light brown 
or tan. 

Legs ivory to cream, without distinct darker markings. 

Labium and endites cream with black scopulae at distal ends 
of endites. Sternum ivory. 

Diagnosis. Oxyopes occidcns is similar to O. aglossus and 
bears some resemblance to 0. aclcistus and 0. aureus. With 
these three species 0. occidens constitutes what is termed in this 
paper the aclcistus species group. O.ryopes occidcns is the largest 
and most divergent member of this group and also the lightest 
in color. It can be easily distinguished from the other members 
of the group by its color pattern ( Figs. 7 and 8) and especially 
the male or female genitalia (Figs. 33, 34 or Figs. 25, 26). 
Oxyopes occidens is the only representative of this species com- 
plex in the western United States. 

Natural history. This spider was collected from very dry, al- 
most dead vegetation (primarily Rumex or "Dock" as it is 
commonly called) located near a pond. It exhibited excellent 
jumping ability, leaping among the dried stalks and leaves of 
Rumex when disturbed. This lynx spider could only be collected 
by quickly grabbing it with the hand. Sweeping of the vegeta- 
tion did not yield a single specimen. 

Distribution. Arizona (Mapl). 



466 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 



uTT^^B" 



a g I s s u s 



POSTERIOR LATERAL EYES 
99 



MILLIMETERS 



1.0 l.I 



1.5 1.4 





acleistus 


CARAPACE WIDTH 
99 


(7) 


, 






^H^^HH 




(30) 


^^^^^^H^ 




agio s s US 

1 1 




(301 1 ■ 

MILLIMETERS 
1 1 


^ 1 c c i d e n s 


(10) 1 1 

1 1 1 1 


1 1 1 1 1 1 



1.5 1.6 1.7 1,8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 



PATELLA -TIBIA T 
99 



o c c i dens 



MILLIMETERS 
< \ < I , I ■ I . I 



J I I 1 I , I , I 



2.3 2.5 2.7 2.» 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 

Diagram 3 — Measurements of the Acleistus Group. 
Modified Diee-Leraas diagrams. The horizontal line represents the ob- 
served range, the open rectangle shows the standard deviation and the 
solid black rectangle indicates the 95 per cent confidence intervals for 
the mean. The mean is denoted by a vertical line and the number of 
specimens measured is given in parentheses. 



BKADV : LYNX SPIDERS OF XOKTII A.MKUICA 4(i7 

Records. Arizona. Maricopa Co.: Piiocnix, 17 Od. 1!)60, 9, 
(H. L. Stahiike). Pima Co.: Sabiiio Poiul, Sabino Canyon, Santa 
Catalina Mtns., 26 June 1960, $ $ (JAB), 10 July 1962, 
4 5 <? :$ (ARB), 2 Auo-. 1962, 9 (JAB); Univ. of Arizona, 
Tucson, 24 July 1962, $ (JAB). Yiiina Co.: Yuma. ;10 June 
1957, $ :r)9 9 (VDR). 

OXYOPES APOLLO sp. l\. 

Figures 41, 42, 47-50, 72-75. Map 2. 

Oxyopes Jtrliu.s: Bryant, litiiO, Psyche, 36(4): 92, fig. 7, $, not 0. helius 
Chamberlin. 

Holotijpc. Male from Eneino, Brooks Co., Texas, 12 May 1952 
(M. Cazier, W. Gertsch, R. Sclirammel) in the American Mu- 
seum of Natural History. The specific name is a noun in ap- 
position after the Greek god Apollo. 

Discussion. The female holotype of Oxyopes helius was des- 
cribed from the Okefenokee Swamp, Georgia, by Chamberlin 
(1929). Bryant (1936) described what she thought was the 
male of 0. helius Chamberlin from Kaufman, Texas, not realiz- 
ing she had a new species, distincth' different from 0. helius, 
a species now placed in the genus Hamataliiva. 

Structure. Length of 30 females, 4.2-6.7 mm. mean 5.2 mm; 
length of 30 males, 3.4 - 4.4 mm, mean 3.8 mm. Order of leg 
length IV-I-II-III. For comparison of certain diagnostic meas- 
urements of 0. apollo to those of other species see Table II and 
Diagram 4. 

Color. Female. Pattern illustrated in Figures 41 and 42. 
Eyes circled in black. Eye region dark brown to black. Face 
yellow-orange or golden with vertical brown stripes beginning 
under ALE, widest at AME, narrowing sharply at the lower 
edge of the clj^peus and continuing diagonally to outer margins 
of chelicerae, midway of basal segment. 

Carapace yellow-orange or golden, mostly glabrous. Wide 
dark brown, irregularly notched and branching submarginal 
stripes beginning below PLE and continuing to posterior thor- 
acic declivity. Vertical sides yellow-orange, clothed with 
scattered white hairs. 

Dorsum of abdomen with broad median cream to white stripe 
from base to tip of spinnerets, enclosing a cream colored lanceo- 
late mark over the cardiac region. BroAvn along margins. Venter 
with wide brown median longitudinal stripe composed of three 
indistinct dark bands enclosing two paler ones. IMedian stripe 
outlined by white, lateral areas brown. 



468 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Legs pale to brownish yellow. Dusky markings heaviest on 
distal ends of femora, proximal ends of tibiae and ventral sur- 
faces of legs. 

Labium brownish yellow to dark brown. Endites brownish 
yellow with outer margins and distal ends darker gray-brown, 
except at anterior tip. Sternum cream to yellow wath dark 
brown around margins. 

Male. Eye region mostly dark brown or black. Cymbium 
and leg segments of palpus dark brown. Face yellow-orange or 
golden with brown stripes originating under ALE, widest at 
AME, narrowing at clypeus and continuing diagonally to 
margin of chelicerae midway the length of basal segment. 
Chelicerae with dark brown distal end. 

Carapace glabrous, yellow to golden wdth submarginal dark 
brow^n longitudinal markings similar to those of the female. 

Dorsum of abdomen with median longitudinal white stripe 
enclosing darker lanceolate mark over cardiac region. Lateral 
areas dark brown or black, sometimes with lighter maculations. 
Venter of abdomen with brown median stripe from epigastric 
furrow to base of spinnerets, enclosed by narrow w^hite or yellow 
stripes. Lateral areas dark brown, usually wath pale spots on 
sides. 

Legs yellow to brownish yellow; dusky markings at distal 
regions of femora, proximal and central portions of tibiae. 
Markings on femora more pronounced ventrally. 

Labium dark brown. Endites dark brown, particularly along 
margins, with interior color sometimes lighter yellow. Sternum 
yellow with dark brown perimeter. 

Diagnosis. Oxyopcs apollo is very similar to 0. floridanus in 
structure, color, and in the form of the female genitalia. The 
chief difference between the two species is in the structure of 
the patellar apophyses of the males (compare Figs. 74, 75 with 
Figs. 78, 79). In 0. apollo the knob of the retrolateral process 
of the apophysis is much larger than in 0. floridayius. The 
specimens of 0. floridanus have a dense clothing of appressed 
white hair covering much of the entire body, including the 
legs, while in 0. apollo the carapace is often glabrous and there 
are fewer hairs scattered over the body. If one handles the 
specimens, the white prostrate hairs are rubbed off, but because 
a great number of specimens of 0. apollo were found to have 
the glabrous carapace, it is probably genuine and not artificially 
produced. Since the geographic ranges of 0. apollo and 0. 



BRADY : LYNX SPIDERS OF NORTH AMERICA 469 

floridanus are completely disjunct, based on the material ex- 
amined, further collections in the interlying area will certainly 
elucidate their relationship. 

In Texas, mature individuals of 0. apollo seem to be most 
abundant from May through August. In tlie soutiiern parts 
of its range, however, adult males and females of this species 
have been collected from March through November. 

Natural history. Not much is known of the habits or habitat 
of 0. apollo despite the large numbers in collections. Oxyopcs 
apollo is sympatric over most of its range with 0. salticus, but, 
unlike 0. aglossus, which often appears in collections of 0. 
salticus, 0. apollo is not taken with 0. salticus. In Arkansas, 
0. apollo lias been captured in pitfall traps, not by sweeping as 
are O. salticus and 0. aglossus. 

Distribution. Tennessee, Missouri, Arkansas south through 
Oklahoma and Texas, west to Arizona and south through Nuevo 
Leon and Chihuahua to Hidalgo (Map 2). 

Records. Tennessee. Roane Co.: 1 mi. E of Kingston, 12 July 
1933, 5 (WI). Missouri. Phelps Co.: Rolla, 9 Sept. 1937, 9 
(RHC). Arkansas. Conway Co.: Morrillton, 25 July 1962 
15 s $ : 9 (HEF). Washington Co.: Fayetteville, Aug. 1909 
$ (R. Thaxter). Louisiana. Ascension Par.: Sorrento, 12 Aug 
1938, $ (AMD). Oklahoma. Harmon Co. : 9 9. Pawnee Co. 
1.5 mi. W of Cleveland, 16 Aug. 1956, 9 (MH). Texas 
Anderson ; Brazos ; Brewster ; Brooks ; Hidalgo ; Kaufman 
Kleberg ; Llano ; Maverick ; Polk ; San Patricio ; Somervell 
Terrell. New Mejcico. Eddy Co. : 16 mi. S of Artesia, 23 Sept 
1950, 9 (WJG). Arizona. Organ Pipe Cactus Nat. Monument 
3-7 Aug. 1910, 9 . 

MEXICO. Tamaulipas. San Pedro, May 1936, ^ :8 9 9 (W. 
A. Green). Santa Teresa, 15 May 1952, 3*9 9 :o (MAC, WJG, 
RS). Nuevo Leon. N of Monterey, 8 Aug. 1942, $ . Chihuahua. 
50 mi. S of Villa Ahumada, 11 June 1939, <5 9 9 o (AMD, LID). 
Hidalgo. 10 mi. N of Ixmiquilipan, 5 July 1941, S (AMD). 

OXYOPES FLORIDANUS Sp. U. 

Figures 43, 44, 51, 76-79. Map 2. 

Holotype. Male from Volusia Co., Florida, 1 Apr. 1939 (H. 
K. Wallace) in the Museum of Comparative Zoology. The 
specific name is an adjective referring to the state of Florida. 

Structure. Length of eight females, 4.0 - 6.3 mm, mean 4.8 
mm; length of two males 8.8 and 4.0 mm. Order of leg length 
IV-I-II-III. For comparison of certain diagnostic measurements 



470 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

of 0. floridanus with those of other species see Table II. 

Color. Female. Pattern illustrated in Figures 43 and 44. Eyes 
circled in black with black band from each, directed toward cen- 
ter of eye hexagon. Eye region dark brown, lighter amber in 
center. Face brownish yellow, pale yellow along lower edge of 
clypeus. Lighter areas clothed with appressed white hair, 
especially along sides of face. Vertical brown stripes beginning 
under ALE, widest at AME, narrowing at cylpeus and continu- 
ing diagonally to lateral margins midway down chelicerae. 

Carapace light, brownish yellow or golden, with irregular 
brown pattern as illustrated in Figure 44. Vertical sides light 
brownish yellow, densely clothed with white hair especially 
along lower margins. 

Dorsum of abdomen with broad median stripe of pale yellow; 
numerous brown chevrons crossing this stripe posteriorly. 
Cardiac region with pale brown lanceolate mark. Clothing of 
ovoid to elliptical flattened hairs forming white patches and 
giving the abdomen a mottled appearance. Venter of abdomen 
with wide dark brown stripe from epigastric furrow to base 
of spinnerets. Median stripe bordered by thin pale brownish 
yellow to cream stripes. Lateral areas paler than median, brown 
mottled with brownish yellow to cream. Entire venter overlaid 
with white hair. 

Legs brownish yellow with dusky markings at distal ends of 
femora and at proximal, central and distal ends of tibiae. Scat- 
tered clothing of white flattened hairs heaviest on femora. 

Labium brown. Endites brownish yellow with dusky lateral 
margins ; distal ends pale cream. Sternum yellow with dark 
brown margin, heavily covered with white appressed hair. 

Male. Eyes circled in black. Eye region dark brown, almost 
black. Iridescent scales between AME. Palpi dark brown to 
black. Face orange-brown with reticulate black markings in 
one specimen, or entire center of face from ALE to clypeus dark 
brown in the other case. Dark median area bounded on each 
side by paler yellow. An indistinct black line from AME to 
edge of clypeus in one specimen. 

Carapace golden brown with wide dark brown longitudinal 
stripes that have irregular branches and indentations (Fig. 
77). Vertical sides golden brown with dense clothing of flattened 
white hair. 

Dorsum of abdomen with central region of pale cream to 
brownish yellow, covered by dense clothing of translucent 
scales. Cardiac region outlined with brown. Lateral area brown 



BRADY : LYNX SPIDERS OP NORTH AMERICA 



471 



witli scattered patelies of white liair posteriorly. Venter with 
wide brown median stripe, margined by pale lines. Lateral area 
brown, mottled with white or yellow. Entire venter covered 
with scattered iridescent scales. Spinnerets pale yellow. 

Legs brownish yellow to yellow with scattered dusky mark- 
ings, more pronounced on ventral surfaces. 

Labium dark brown. Endites dark brown with inner margins 
of distal ends pale. Sternum yellow with dark brown margin. 

Diagnosis. Ojcyopcs jluridanus is very similar to 0. apollo. 
The primary differences are in the patellar apophyses of the 
males (compare Figs. 78, 79 with Figs. 74, 75). Since 0. flori- 
danus is completely allopatrie to 0. apollo, it may be considered 
only as a geographic race of 0. apollo when more information 
becomes available. There are no perceptible ditferenees in the 
male palpus of 0. apollo throughout its range from Tennessee 
to northern Mexico. The male palpus of 0. floridanus, however, 
is diiferent from 0. apollo, and I suspect that this difference 
would be one of the first brought about by selection pressure 
during the process of speciation. It appears to me that 0. 
floridanus is isolated from 0. apollo, not only geographically, but 
genetically as well. 

Distribution. Florida (Map 2). 

Records. Florida. Desoto Co.: Peace River near Arcadia, 30 
Mar. 1938, 69 9 (WJG). Duval Co.: 17 Apr. 1949, $. Lake 
Co.: Altoona, 9 9 (NB). Levy Co.: 2 Mar. 1946, o (HKW). 
Volusia Co.: 1 Apr. 1939, $ (ilKW). 




Map 2 



472 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

OXYOPES TRIDENS Sp. n. 

Figures 45, 46, 53-55, 62, 63, 70, 71. Map 2. 

Holotype. Male from Mercury, Nye Co., Nevada, 4 July 1961 
(CBA3C) in the American Museum of Natural History. The 
specific name is an adjective meaning trident. 

Structure. Length of 26 females 5.5-7.6 mm, mean 6.3 mm; 
length of 25 males 4.9 - 6.4 mm, mean 5.5 mm. Order of leg 
length IV-I-II-III. For comparison of certain diagnostic meas- 
urements of 0. tridens with those of other species see Table II 
and Diagram 4. 

Color. Female. Pattern illustrated in Figures 45 and 46. Eye 
region dark brown with streak of white hairs running from 
PLE and ALE to PME where it joins white hair of face. Face 
white from dense clothing of flattened hairs. Wide vertical dark 
brown stripes originating under ALE, diminishing in size at 
lower edge of clypeus and continuing to subdistal region of 
chelicerae. Inner margins and distal ends of chelicerae brown. 

Carapace with broad central longitudinal white region, clothed 
entirely with white hair. Anteriorly this hair forms a trident, 
the middle prong going between the PME and each of the 
lateral prongs pointing to a PLE. Broad submarginal stripes 
of dark brown beginning under ALE and continuing to thoracic 
declivity. Vertical sides of carapace white. 

Dorsum of abdomen with median longitudinal white stripe 
from base to spinnerets, enclosed on each side by dark brown 
or black. The dark lateral areas sometimes mottled with white. 
Venter of abdomen with median brown stripe from epigastric 
furrow to base of spinnerets, bordered on each side by a thin 
white line. Lateral area brown, but entire venter often with a 
clothing of white hairs moderating darker colors. 

Legs pale yellow with dusky streaks, especially on ventral 
surfaces of femora and tibiae. Scattering of white hairs over 
lower leg surfaces is common. Distal segments are usually some- 
what darker. 

Endites cream to light brownish yellow with outer margins 
and sometimes inner margins dusky. Distal ends ivory with 
black scopulae. Labium pale yellow, grayish along sides with 
anterior edge ivory. 

Male. Pattern illustrated in Figures 62 and 63. Eye region 
with fewer white hairs than in female. Palpi dark brown or 
black. The color and markings of the face, carapace, abdomen, 



BRADY : LYNX SPIDERS OF NORTH AMERICA 473 

legs and other parts of the body are like those of the female 
and there is very little dimorphism between the sexes. 

Diagnosis. Oxyopes tridens is similar in coloration to 0. 
pardus, 0. lynx and 0. felinus. Together with these species it 
forms a distinct species complex related to 0. floridaiius and 
0. apollo in the East. All of the species found in the West ap- 
pear much the same, with a longitudinal white stripe bordered 
by black stripes extending the length of the l)ody. Oxyojyes 
tridens is the species most often collected in Arizona and the 
male is easily separated from other species in this group by 
the patellar apophysis of the palpus (Figs. 70, 71). The female 
of 0. tridens is readily identified by the shape of the epigynum 
(Figs. 53-55), but to date the females of 0. pardus, 0. lynx and 
0. felinus have not been collected and it is not known how^ much 
they differ from 0. tridens. 

Natural history. According to W. J. Gertsch (pers. com.) this 
species is only rarely found on vegetation. It is often seen 
jumping over rocks in rough outcrops and running over bare 
ground. This lynx spider has also been collected from the walls 
of buildings. Of the species I have collected that belong to 
the tridens group, none were found on vegetation. Several were 
collected in areas where moss was growing and moisture was 
readily available, but others were collected as they were hopping 
about over rather dry hillsides. All of my specimens but one 
are males, however, and these tend to wander more than the 
females. It is possible that the members of the tridens group do 
not commonly occur on vegetation, as do most other lynxes, but 
prefer barren hillsides, bare rock outcrops and similar habitats. 
In many of the vials of 0. tridens examined during this study 
only one specimen was present, and only four vials contained 
more than three specimens. This suggests that 0. tridens has 
probably not been collected much by sweeping, since many 
specimens are found in a single vial where this method is em- 
ployed. This provides indirect evidence as to the habitat pref- 
erences of 0. tridens. 

Distrihution. Western Texas to southern Nevada and Cali- 
fornia, south to Sonora and Coahuila (Map 2). 

Records. Texas. Brewster Co. : Marathon, 1-2 July 1916, 
3 5 9 (F. E. Lutz) ; top of Chisos Mtns., Big Bend Nat. Pk.. 
25-26 July 1933, 9 (SM). Arizona. Maricopa Co.: Phoenix, 
summer 1959, G S S . Pima Co. : Organ Pipe Cactus Nat. ]\Ionu- 
ment, 9 9 , 14 June 1952, 7oo (MAC, WJG, RS), 3-7 Aug. 1910, 



474 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

9 9,4-7 Aug. 1916, 9 ; Sabino Canyon, Santa Catalina Mtns., 1 
Sept. 1939, 9 (RHC), 3 Sept. 1950, 9 (WJG) ; Tucson, £ $ 
(0. Bryant), May 1940, o, 20 May 1941, 9 (RHC), 20 June 
1961, S , 20 Aug-. 1961, $ (JAB). Yuma Co.: Yuma, May 1958, 

S, May-June 1956, S, 30 June 1957, 3 5 5 :4 9 9 :o (VDR). 
Nevada. Nye Co. : Mercury, 24 June 1961, S , 29 June 1961, 

9 , 4 July 1961, $ , 14 July 1961, $ , 18 July 1961, S , 25 July 
1961, 9 . California. Imperial Co. : Palo Verde, 14 June 1961, 

$ (VDR). Los Angeles Co. : Acton, 5 Aug. 1931, 9 (AVI). San 
Bernardino Co. : Twenty-nine Palms, 1-15 July 1945, $ , July- 
Aug. 1945, 3$ $ (J. H. Branch). San Diego Co.: 5 mi. E of 
Jacumba, 9 July 1960, o(W. F. Barr). 

MEXICO. Coahuila. La Gloria, 24 Aug. 1947, 9 (WJG) ; 
20 mi. E of San de las Colonias, 5 July 1936, 9 (AMD, LID). 
Chihuahua. Samalayuca, 25 June 1947, $ (WJG). Sonora. El 
Desemboque, 1-10 Sept. 1953, S (BM) ; 25 km S of Desemboque, 
11 Aug. 1953, 9 (BM) ; 10 mi. S of Hermosillo, 16 June 1939, 

9 (AMD, LID). 

OXYOPES PARDUS Sp. n. 

Figures 60, 61, 68, 69. Map 2. 

Holotype. Male from South Fork of Cave Creek Canyon, 
Chiricahua Mtns., Cochise Co., Arizona, 8 July 1962 (J. A. 
Beatty) in the Museum of Comparative Zoology. The specific 
name is a noun in apposition meaning panther. 

Structure. Length of two males 4.7 and 5.0 mm. Order of 
leg length IV-I-II-III. For comparison of certain diagnostic 
measurements of 0. pardus with those of other species see 
Table II. 

Color. Male. Pattern illustrated in Figures 60 and 61. Eye 
region glossy black. Palpi black, thickly clothed with black hair. 
Irid&scent scales between ALE and scattered over clypeus. Face 
black, with lateral areas paler. 

Black color from face continuing posteriorly as two broad 
submarginal stripes, bounded laterally by yellow. Central area 
of carapace pale yellow. Vertical sides below black stripes yel- 
low, clothed with white hairs especially along margins of cara- 
pace in one specimen. 

Dorsum of abdomen with broad median stripe of yellow, 
clothed with white hair, bordered on each side by black. In one 
specimen the black is mottled with yellow. In the other, the 



BRADY: lA'NX SPIDERS OF XORTI I A.MI;KICA 475 

pale median stripe becomes suffused witli gray posteriorly. 
Venter with broad median dark band from epigastric furrow to 
spinnerets, bounded on each side by lighter yellow spotted with 
black in one case. Tn the otlier specimen, the venter is entirely 
black with abundant iridescent scales. This specimen also has 
iridescent scales on ventral surfaces of femora. 

Legs yellow, but with femora appearing gray due to dusky 
markings. Tibiae and more distal leg segments i)aler yellow ; 
one specimen lias the ventral surface of leg segments dusky. 

Endites and labium black with distal ends white. Sternum 
cream colored with gray around margin. 

DiagnosU. Oxyopcs pardiis is similar in coloration to 0. iri- 
dens, 0. lynx and 0. felinus. All four of these species have the 
same general coloration (Figs. 56-63). The face of 0. pardus is 
much darker than any specimens of the other three species, and 
it is immediately recognized l)y the form of the patellar apophy- 
sis (Figs. 68, 69). In addition to similar color patterns, the 
males of the four species above, with the exception of 0. felinus, 
each have a well-developed apophysis on the patella, as well as a 
modification of the tibia. 

Natural history. One male of 0. pardus was collected in the 
late morning as it was jumping from rock to rock over a rather 
barren hillside. The other specimen was collected as it ran across 
an open trail with little ground cover. 

Records. Arizona. Cochise Co.,: Chiricahua Mtns., South Fork 
of Cave Creek Canyon, 8 July 1962, $ (JAB) ; Southwestern 
Research Station, 6 July 1962, i (ARB). 

OXYOPES LYNX Sp. R. 

Figures 58, 59, 66, 67. Map 2. 

Holotype. Male from Marathon, Brewster Co., Texas, 12 June 
1948 (M. A. Cazier) in the American Museum of Natural His- 
tory. The specific name is a noun in apposition after the Lynx. 

Structure. Length 5.0 mm. Order of leg length IV-I-II-III. 
For comparison of certain diagnostic measurements of 0. lynx 
with those of other species see Table II. 

Color. Male. Pattern illustrated in Figures 58 and 59. Eye 
region black with lighter yellow area in center of hexagon. Face 
yellow-orange or golden. Vertical stripes of a darker brownish, 
beginning under ALE and continuing to lower edge of chelicerae, 
only faintly indicated on chelicerae. 



476 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Carapace with median area yellow. Dark brown submarginal 
stripes from eye region to posterior declivity. Marginal vertical 
sides clothed with white pubescence. 

Dorsum of abdomen with broad white median longitudinal 
stripe from base to tip of anal tubercle, bordered on each side 
by black. Black regions with translucent scales. Venter of abdo- 
men dark brown, almost black with translucent, iridescent 
scales present. 

Legs yellow with faint dusky markings on ventral surfaces. 

Labium and endites yellow. Sternum cream colored with faint 
dusky markings along margin. 

Diagnosis. Oxyopes lynx is related structurally and in general 
color pattern to the western members of the tridens species 
group, including that species, 0. pardus and 0. lynx. Oxyopes 
lynx is identified by the peculiar shape of the patellar apophy- 
sis (Figs. 66, 67) that separates it distinctly from these closely 
related species. 

Chamberlin and I vie (1944) described a species from the 
Georgia region of the United States and identified it as 0. 
lanceolatus (Walckenaer). Their illustration (Chamberlin and 
Ivie, 1944, fig. 180) is a retrolateral view (similar to Fig. 66) 
showing the patellar apophysis. The apophysis of 0. lanceolatus 
figured by Chamberlin and Ivie bears a strong resemblance to 
that of 0. lynx, and 0. lanceolatus undoubtedly belongs in the 
tridens species group. Unfortunately, the specimen of 0. lanceo- 
latus has been misplaced or lost and was not available for exam- 
ination. An investigation of eastern material did not reveal any 
specimens resembling its description. 

Natural history. Presumably 0. lynx is similar in ecology to 
other members of the tridens group. Refer to the discussion 
under the natural history of 0. tridens. 

Records. Texas. Brewster Co. : Marathon, 12 June 1948, $ 
(MAC). 

Oxyopes felinus sp. n. 
Figures 56, 57, 64, 65. Map 2. 

Holotype. Male from Molino Basin, Santa Catalina Mtns., 
Pima Co., Arizona, 12 July 1962 (A. R. Brady) in the Museum 
of Comparative Zoology. The specific name is an adjective 
meaning cat-like. 

Structure. Length of male 4.6 mm. Order of leg length IV-I- 



BRADY: LYNX SPIDERS OF NORTH AMERICA 477 

II-III. For comparison of certain diagnostic measurements of 
0. fclinus with those of other species see Table IT. 

Color. Male. Eye region black, iridescent scales from ALE to 
AME. Palpi black. Face yellow-orange or golden, with two 



I ^ I 



opol lo 



(2) 1 I 



., [=^ 



POSTERIOR LATERAL EYES 



t rid e n s 





r~ 


-^ 


apollo 


POSTERIOR LATERAL EYES 
99 




(30) 1 


-W 


1 1 






,.," 


4- 


floridonus 






■J 










r-^- 


t r i d e n s 

] 




..., L-^ 




MILLIMETERS 

1 


1 


1 


1 I 


1 1 1 


0.8 


0.9 

1 


1.0 


1.1 1.2 


1.3 1,4 l.i 

CARAPACE WIDTH 

9? 




^H 


^HH 






^^ 


^^^H 


j 






..:-^ 


m^ 


ori d onu s 


1 r i d e n s 




(24) 


^ 




MILLIMETERS 
1 1 


1 1 


1 


1 -1 1 


1 1 1 , 1 


1.3 1.4 


l.S 1.4 


1.7 

"1 


1.8 1.9 2.0 

apollo 


2.1 2.2 2.3 2.4 2.; 

PATELLA-TIBIA I 
99 



floridonus 



!5T~tl^P^^ 



MILLIMETERS 

1 i__J . i , 1 ^ I : I , 1 . 1 1 I I 1 . 1,1,1 

'•' 1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.4 3.8 4.0 

Diagram 4 — Measurements of the Apollo Group. 
For interpretation refer to Diagram 3. 



478 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

broad vertical black stripes beginning at ALE and continuing 
to subdistal region of chelicerae. Few scattered scales on face. 

Carapace pale yellow. Broad submarginal black stripes from 
eye region to posterior declivity. Vertical sides of carapace pale 
yellow. 

Dorsum of abdomen with white median longitudinal stripe 
from base to tip of spinnerets, bordered on each side by jet black. 
Venter of abdomen black with metallic sheen of lavender or 
green. Kegion above epigastric furrow yellow with black patch 
over the genital region. 

Legs yellow with slight dusky markings on ventral surfaces. 
Legs much lighter than in 0. pardus. 

Labium yellow with black margins, not heavily scopulate. 
Endites yellow with black scopulae. Sternum pale yellow with 
diLsky marginal markings. 

Diagnosis. Oxyopes felinus is similar in coloration to 0. tri- 
dens, 0. lynx and 0. pardus. It does not have a conspicuous 
patellar apophysis as in the other western species of the tridens 
group, but the color pattern, relative length of the legs and geni- 
talia relate it to this group. Oxyopes felinus is most easily recog- 
nized by the structure of the male palpus (Figs. 64 and 65). 

Natural history. The single male specimen was collected as 
it ran over very dry vegetation on a rocky slope. 

Record. Arizona. Pima Co. : Molino Basin, Santa Catalina 
Mtns., 12 July 1962, $ (ARB). 

Oxyopes salticus Hentz 
Figures 80-86, 91-96, 104-105. Map 3. 

Oxyopes salticus Hentz, 1845, Boston Jour. Nat. Hist., 5:196, pi. 16, fig. 
10, 9 . Female syntypes from North Carolina and Alabama, lost. 
Hentz, 1875, Occ. Pap. Boston Soc. Nat. Hist., 2:47, pi. 6, fig. 10, 9. 
Emerton, 1902, Common Spiders of the U. S., Boston, p. 88, figs. 218- 
219, $,9. Montgomery, 1902, Proc. Acad. Nat. Sci. Philadelphia, 54: 
590, fig. 52, 9 . Comstock, 1912, The Spider Book, p. 660, fig. 773, 9 ; 
op. cit., rev. ed., 1940, p. 668, fig. 733, 9 . Chamberlin, 1929, Ent. News, 
40:18, fig. 5, 9. Kaston, 1948, Bull. Connecticut State Geol. Nat. Hist. 
Survey, 70, figs. 1147-48, 9 . Koewer, 1954, Katalog der Araneae, 2(a) : 
333. Bonnet, 1958, Bibliographia Araneorum, 2(4):3240. 

Oxyopes astutus Hentz, 1845, Boston Jour. Nat. Hist., 5:197, pi. 17, fig. 1, 
$ . Male holotype from Alabama, lost. 

Oxyopes gracilis Keyserling, 1877, Verh. Zool.-Bot. Ges. Wien, 26:698, pi. 2, 
figs. 63, 64, 9 (in part, but not type). 



BRADY : lA'NX SPIDERS OF NORTH AMERICA 479 

Discussion. Oxyopcs ashih(s lleiit/., is the male of (). salticus. 
Oxyopes lutcus Blackwall (1862) and (). rarians Tac/.aiiowski 
(1873), described from Brazil and Frencli (iuiana, respectively, 
have been erroneously placed in synonymy with 0. salticus (see 
Bonnet, 1958, and Roewer, 1954). Keyserlinw (1877) described 
0. (jracilis from the United States, Central and South America. 
He -was dealing with several species. Syntypes are from New 
Granada (Panama, Ecuador, Peru, Colombia, Venezuela) and 
this name should be associated with the Central and South 
American species of Oxyopes. The species described as 0. gracilis 
Key.serling by P. 0. Pickard-Cambridg'e (1902) is one of the 
most common Oxyopes of Mexico and Central America, and is 
very similar to 0. salticus. The male palpus of 0. gracilis (Figs. 
102, 103) is distinct from O. saUicus (Figs. 104, 105) and so far 
a.s I have determined 0. gracilis occurs from central Mexico 
southward to Brazil. Oxyopes salticus apparently reaches the 
southern limit of its range in northern Mexico. 

Banks (1902, 1903, 1909) reports 0. salticus from Puerto 
Rico, Haiti, and Cuba. I have examined very extensive collec- 
tions from Cuba and smaller ones from Haiti and Puerto Rico 
and 0. salticus does not appear in these. Instead, Banks was 
probably dealing with a closely similar, but very distinct species 
described from Haiti by Bryant (1948). This species, 0. crewi 
Bryant, is abundant in collections from Cuba and evidently 
replaces 0. salticus on the island.s of Cuba, Haiti and Puerto 
Rico. 

Structure. Length of 30 females 4.6-7.4 mm, mean 5.9 mm; 
length of 30 males 3.9-5.9 mm, mean 4.7 mm. Order of leg 
length I-II-IV-III or T-TI=IV-III. For comparison of certain 
diagnostic measurements of 0. salticus with those of other species 
see Table II and Diagrams 5 and 6. 

Color. Female. Pattern illustrated in Figures 85 and 86. 
Eye region heavily clothed with white appressed hairs; when 
rubbed off, the eye region is dark brown to black. Face cream 
to ivory, white along lower edge of clypeu.s and distal ends of 
chelicerae. Black markings along posterior margins or "cheeks" 
of face as in Figure 85. Vertical black lines from AME to sub- 
distal region of chelicerae. 

Carapace pale cream to ivory, with two pairs of dark lines 
formed by flattened hairs, beginning behind PLE and continuing 
to thoracic declivity. 

Dorsum of abdomen white with cardiac region clothed with 



480 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

white hair and outlined with brown. Two brown stripes pos- 
terior to cardiac region formed by appressed hairs. Lateral areas 
of abdomen dark brown to black with irregular streaks of white 
hair on the sides. White pigment deposited beneath the integu- 
ment so that if the clothing of white and contrasting brown hair 
is rubbed off, the abdomen appears chalk white with the cardiac 
area translucent white and no darker color laterally. Venter 
of abdomen with a wide median stripe of brown to black from 
epigastric furrow to base of spinnerets. Spinnerets pale cream 
to yellow. Median stripe bounded by white. Lateral areas pale 
yelloAv. 

Legs pale yellow to cream with longitudinal black stripes 
on ventral surfaces of femora I, II and III ; absent on IV. 

Endites pale yellow to cream with distal ends ivory; scopulae 
black. Labium pale yellow with gray along lateral margins, tip 
ivory. Sternum pale yellow to cream. 

Male. Patterns illustrated in Figures 80-84. Eyes with black 
band extending from each toward center of eye hexagon. Center 
of hexagon pale yellow or cream. Eye region glossy ; no clothing 
of white hairs. Iridescent scales between ALE. Face pale yellow 
to cream. A pair of black marks at margins of face as illustrated 
in Figure 81. Vertical black lines from AME to subdistal region 
of chelicerae. Distal ends of chelicerae pale cream. Face be- 
tween black lines black, and black on chelicerae as indicated in 
Figure 81, or the vertical lines alone are black as in Figure 83. 

Carapace pale yellow to gold with scattering of spatulate ap- 
pressed hairs sometimes forming faint longitudinal stripes, but 
never as distinctly as in the female. 

Dorsum of abdomen black with covering of iridescent scales 
giving it a metallic lavender or blue-green luster (Fig. 82). In 
the field these scales make the abdomen appear golden in bright 
sunlight. The abdomen ranges from black, as above, to pale 
yellow tinged with gray (Fig. 84). Cardiac region gray, out- 
lined with pale yellow ; scattered glistening scales on the dorsum 
of lighter individuals. Venter of abdomen black with metallic 
blue-green or lavender sheen posterior to epigastric furrow. Black 
patch over genitalic region with areas lateral to this patch yellow. 
This pattern is found in dark specimens as in Figure 82. The 
venter may also have a wide median stripe of brown to black, 
margined with pale lines and the lateral areas pale brownish 
yellow. This coloration is found in light individuals, as in 
Figure 84. 



BRADY : LYNX SPIDERS OF NORTH AMERICA 481 

Legs pale yellow to cream. Distinct black longitudinal lines 
on ventral surfaces of femora I, 11, III; absent in IV. 

Eudites yellow to cream with black shading on outer margins 
or without dusky markings. Labium darker, sometimes brown 
Avith distal end pale yellow or cream. Sternum pale yellow or 
cream, usually with black spots around margin. 

Diagnosis. Oxyopcs salticus resembles the members of the 
acleisius group in coloration. The black stripes on the femora 
and the vertical black lines on the face are as in 0. aglossus. 
Oxyopcs salticus is immediately identified by the peculiar shape 
of the epigynum (Figs. 91, 93, 96) and the characteristic palpus 
of the male (Pigs. 104, 105). The male palpus has a very stout 
conical protrusion ol" the cymbium not as well developed in any 
other species of Oxyopes north of Mexico. Also, a stout brush 
of short, stiffened bristles (not figured) on the ventral surface 
of the palpal tibia separates the male of 0. salticus from all other 
males. 

Natural history. Oxyopcs salticus is one of the most common 
spider inhabitants of tall grass and herbaceous vegetation and is 
found throughout the United States wherever this type of vegeta- 
tion occurs. During certain seasons, usually mid-June to Sep- 
tember, these lynx spiders can be collected in great numbers from 
vegetation with the aid of a sweep net. The local abundance 
of these spiders gives evidence of their role as one of the chief 
predators of insects occurring in grassy or weedy fields and 
similar habitats. Evidently 0. salticus is an important predator 
of certain crop insects, such as those on cotton (Whitcomb, et 
al., 1963). 

A.s it seeks prey over leafy or grassy vegetation, 0. salticus 
assumes a characteristic pose, raising and extending the long 
front legs and resting on its hind legs. This prey-catching 
posture is similar to the attitude of some misumenoid crab 
spiders. Unlike the crab spiders, however, this lynx spider moves 
about stealthily and pursues its prey more readily, thanks to 
relatively keen eyesight. If alarmed, 0. salticus bounds and 
springs over and through the vegetation with great energj' and 
agility. The leaps of this lynx spider exceed even those of most 
of the salticids, renowned for their jumping ability. Oxyopes 
salticus is more slender than most Salticidae and its fourth pair 
of legs is stoutly constructed and well suited for hurling this 
spider through the air. 

Several leaves of grass or similar vegetation are tied together 



482 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

by 0. salt ic us or it employs an appropriate small bush or plant 
to deposit its egg ease. Once the egg case is constructed it is fixed 
among the leaves and twigs with many silken lines forming a 
tangled meshwork of silk. The female then stands guard over 
its future progeny much as a mother hen sitting on her nest 
of eggs. In several hundred vials containing 0. salticus, only 
two egg cases were discovered. These were roughly spherical 
and about 3.5 mm in diameter; one contained 55 spiderlings 
and the other 18-20 eggs, each a little less than 1 mm in diam- 
eter. The extreme rarity of egg cases in collections is probably 
due to the method used in collecting these spiders. In sweeping, 
the spiders are dislodged from the vegetation, but the egg cases 
remain firmly attached. 

Bistribuiion. Throughout the United States (Map 3). 

Records. County records only are listed. For complete records 
refer to the Doctoral Dissertation. New Hampshire. Hillsboro. 
Connecticut. Fairfield; New Haven. New York. Livingston; 
Nassau; Suffolk; Ulster; Westchester. New Jersey. Bergen; 
Morris; Ocean. Ohio. Knox. District of Columbia. West Vir- 
(jinia. Marion ; Pleasants ; Pocahontas ; Upshur. Virginia. Arling- 
ton ; Bath; Fairfax; Giles; Page; Pittsylvania; Rockingham. 
Kentucky. Breathitt; Jefferson. Tennessee. Hamilton; Knox; 
Loudon ; Roane ; Robertson. North Carolina. Avery ; Buncombe ; 
Burke; Carteret; Durham; Guilford; Haywood; McDowell; 
Mitchell ; Orange ; Transylvania ; Wake ; Yancey. South Carolina. 
Charleston; Kershaw. Georgia. Clarke; Dade; Floyd; Fulton; 
Thomas; Ware. Florida. Alachua; Citrus; Desoto ; Duval; High- 
lands; Hillsborough; Indian River; Jackson; Lake; Martin; 
Orange; Palm Beach; Pasco ; Pinellas; Sarasota; Volusia. Ala- 
lama. Baldwin; Covington; Escambia; Lee; Montgomery; 
Morgan; Tallapoosa. Mississippi. George; Hinds; Jackson; La- 
fayette; Oktibbeha; Wilkinson. Louisiana. Caddo; East Baton 
Rouge ; Grant ; Lincoln ; Madison ; Natchitoches ; Orleans. Michi- 
gan. Midland. Indiana. Green; Posey. Wisconsin. Lafayette. 
Illinois. Champaign; Washington. Iowa. Story. Missouri. Boone; 
Carter; Dent; Jackson; Phelps. Arkansas. Conway; Crawford; 
Deshea; Hempstead; Jefferson; Lincoln; Washington. Nebraska. 
Buffalo; Lancaster; Saline. Kansas. Douglas; Greenwood; Jef- 
ferson; Kingman; Meade; Montgomery; Rooks; Washington. 
Oklahoma. Comanche ; Grady ; Harmon ; Pawnee. Te.ras. Austin ; 
Bexar ; Bowie ; Brazos ; Burleson ; Burnet ; Cameron ; Cherokee ; 
Dallas ; Harris ; Hays ; Hidalgo ; Hudspeth ; Jasper ; Jim Wells ; 



BRADY : LYNX SPIDERS OF NORTH AMERICA 



483 








484 BULLETIN : MUSEUM OF COMPARATIVE ZOOLOGY 

Lamar ; Liberty ; Llano ; McLennan ; Mills ; Navarro ; Newton ; 
Panola ; San Patricio ; Shelby ; Somervell ; Taylor ; Travis ; 
Uvalde ; Wichita ; Williamson ; Wise. Ariz07ia. Cochise ; Mari- 
copa ; Yuma. Oregon. Benton ; Douglas ; Jackson ; Yamhill. Cali- 
fornia. Humboldt ; Imperial ; Kern ; Lake ; Los Angeles ; Marin 
Mendocino ; Monterey ; Riverside ; San Diego ; San Francisco 
San Joaquin ; Santa Barbara ; Santa Clara ; Shasta ; Stanislaus 
Ventura. 

MEXICO. Nuevo Leon: 32 mi. SW of Laredo. 

OxYOPES scALABis Hentz 
Figures 87-90, 97-99, 106, 107. Map 4. 

Oxyopes scalaris Hentz, 1845, Boston Jour. Nat. Hist., 5:196, pi. 17, fig. 
4, 9 . Female syntypes from North Carolina, lost ; ihid., 1875, Occ. 
Pap. Boston Soc. Nat. Hist., 2:47, pi. 7, fig. 4, pi. 19, fig. 120, $. 
Emerton, 1885, Trans. Conn. Acad. Arts Sci., 6:502, pi. 49, fig. 11, $, 
Comstock, 1912, The Spider Book, p. 660; op. cit., rev. ed., 1940, p. 
668. Chamberlin, 1929, Ent. News, 40:18, fig. 6, 9. Kaston, 1948, 
Bull. Connecticut State Geol. Nat. Hist. Surv., 70:340, pi. 59, fig. 
1149, 5. 

Oxyopes laminatus Tullgren, 1901, Bih. Svensk. Vet. Ak. Handl., 27 
(4, 1) :24, pi. 1, fig. 14, 9. Female holotype from Orange Co., Florida, 
in Zoologiska Inst., Uppsala. 

Oxyopes cinerea Banks, 1893, Jour. New York Ent. Soc, 1:133. Syntypes 
from New Hampshire in American Museum of Natural History, exam- 
ined. NEW SYNONYMY. 

Oxyopes rufipes Banks, 1893, Jour. New York Ent. Soc, 1:133. Syntypes 
(5:69 9) from Olympia, Thurston Co., Washington, in Museum of 
Comparative Zoology, examined. NEW SYNONYMY. 

Oxyopes compacta Banks, 1896, Trans. Amer. Ent. Soc, 23:72. Syntypes 
(3oo) from Fort Collins, Larimer Co., Colorado, in Museum of Com- 
parative Zoology, examined. NEW SYNONYMY. 

Oxyopes pictipes Banks, 1901, Proc Acad. Nat. Sci. Philadelphia, 53:r)87. 
Female holotype from Albuquerque, Bernalillo Co., New Mexico in 
Museum of Comparative Zoology, examined. NEW SYNONYMY. 

Oxyopes classicus Chamberlin, 1925, Proc. Calif. Acad. Sci., 14(4): 126, 
fig. 38, 9 . Female holotype from Altoona, Lake Co., Florida, in 
Museum of Comparative Zoology, examined. NEW SYNONYMY. 

Oxyopes tanneri Chamberlin, 1928, Canad. Ent., 60(4) :95. Female holotype 
from the La Sal Mtns., Utah, in the collection of R. V. Chamberlin, 
Univ. of Utah, misplaced or lost. NEW SYNONYMY. 
Discussion. Oxyopes scalaris is the most widespread of the 

lynx spiders considered in this investigation. The shape of the 



BRADY : LYNX SPIDERS OF NORTH AMERICA 485 

epigynum varies somewhat among individuals and the color pat- 
tern exhibits a great amount of goograpliical variation. These 
two facts have produced an al)Uiidance of names in the literature 
for this species. Oxyopcs laminatus and 0. classicus were de- 
scribed from Florida, and 0. tanncri from Utah. Banks (1893) 
gave two new names to this species, one to specimens from the 
state of Washington (O. rufipcs) and another to specimens from 
New Ilamp.shii-e (O. cinerca). The separation of these two popu- 
lations was based on whether the cephalic region of the carapace 
was elevated above the thoracic region, or on a level with it. If 
large series are examined, this character varies within the same 
local populations. The name 0. rufipcs has often been applied 
to western populations of 0. scalaris, but only a single species is 
involved. Chamberlin (1923) used the same criterion as Banks 
to separate 0. scalaris from 0. rufipcs. In addition, 0. scalaris 
was supposed to have a narrower finger (scape) on the epigynum 
than 0. rufipcs. The width of the scape also varies in specimens 
from the same locality as much as it does geographically. Gertsch 
recognized this synonymy in 1949. Banks (1904) synonymized 
0. laminatus Tullgren with 0. scalaris. Oxyopcs tanncri, judg- 
ing by its description and locality, is probably 0. scalaris. 

Structure. Length of 30 females 5.8-9.6 mm, mean 6.9 mm; 
length of 30 males 4.7-6.1 mm, mean 5.5 mm. Order of leg 
length I-II-IV-III. For comparison of certain diagnostic meas- 
urements of 0. scalaris with those of other species see Table II 
and Diagrams 5 and 6. 

Color. The coloration of (). scalaris varies greatly not only 
geographically, l)ut within the